GEOGRAPHY AND YOU

GeoGraphy and you.com

Vol. 13, Issue 79, July - auGust 2013 `60

A De v e l op m e n t A n D e n v i ron m e n t m Ag A z i n e

earth rth sscIence c ence

technoloGIes technolo GIes Landslide Prediction in India Remote Sensing Applications Farming the Seas Weather Modelling

GeoGraphy and you Vol. 13  Issue 79  July - AuGusT 2013

Future Earth 6

View Point

The 2013 Uttarakhand Floods: Two faces of a Disaster

Vinod Tare and Gautam Roy

8

The Alaknanda Disaster: A result of ‘River Space’ Incursion

Rajiv Sinha

10

Advance Warning System for Uttarakhand

J Srinivasan

12

earth Science technologieS

Extreme Events Weather Service for Indian Agriculture

34

A K Gosain

38 44

24 30

Remote Sensing Applications

J S Parihar, A S Rajawat and Prakash Chauhan

48

Calculating Carbon Uptake by the Oceans

Gas hydrates in Krishna-Godavari offshore basin Predicting Poor Air Quality Events

Gufran Beig and Neha Parkhi

52

Rewiring The Tsunami Early Warning System

M V Sunanda, T Srinivasa Kumar, Dipankar Saikia, S S C Shenoi, Shailesh Nayak

56

Ecosystem Services from Marine Living Resources

V N Sanjeevan and Asha Devi C R

Farming the Seas

R Kirubagaran and M A Atmanand

Weather Modelling

Swati Basu and E N Rajagopal

T Ramprasad, A Mazumdar and P Dewangan

N Chattopadhyay, L S Rathore

18

Geospatial Framework for Water Resources

62

concePt counter

Geographical Knowledge through Quantitative Methods

Sucharita Sen

R Ramesh

2 Editor’s Note 3 Letters

68

4 News Brief 17 Term Power 23 Ozone 29 Term Rating

72

in Brief

india outdoorS

Kanchenjunga Cheated Me Sulagna Chattopadhyay

The Jhora of Sikkim

Satellite and ground measurements only record certain parameters and it’s difficult to compare measurements from different instruments. The answer to these challenges is data reanalysis—putting all available real-world data into a single model and running it consistently for an extended period of time. The reanalysis project at NASA’s Goddard Space Flight Center combines all information in the GEOS model. Source: NASA GeoGraphy and you  july - auGust 2013  1

E ditor’s Note Monsoon over the darjeeling Hills

Dear readers

Our learnings about earth systems begin from pre-puranic times when man started working out the hows and whys of storms, eclipses, monsoon and so on. Modern earth science however has specialised its outlook with well defined study areas, which broadly encompasses geology, meteorology, oceanography and astronomy. In India each area of study falls under the purview of multiple government and autonomous institutes which, in events of disasters like the Uttarakhand tragedy believe in simply passing the buck as accountability is alien to our government setup.

Uttarakhand tragedy could have been minimised. Yes indeed it could—if only we took science seriously and if scientists took the aam admi seriously. ‘So far and no further’ attitude of the scientific domain, has made the science of prediction a farce. Scientific milestone without end-users is like having a lock but losing the key. Its people-unfriendly systems alienate the common man who would rather believe the conniving, corrupt politician than the rather ‘well read’ but totally incommunicado scientists.

So we have tragedy after tragedy. The building heights in mountainous areas reach new highs each time, the fragile roads are relentlessly broadened, river systems increasingly burdened, etc. The vulnerability indexes, the micro zonations and more of all that, are all in place with crores being wasted to process them with consortium after consortium making brisk business—yet they never get past the haloed academia. We have in fact created a new world record where more than 10,000 people have lost their lives, yet no one in the decision-making system has been held accountable.

This issue of G’nY traces all the new happenings in the domain of earth science technologies. A safer future being the focus, the articles range from ocean related sciences to land driven ones contributed by renowned scientists from all over the nation.

Happy reading.

Sulagna Chattopadhyay 2  july - August 2013  geogrAphy And you

L etters

For more details log on to our website www.geographyandyou.com

Curbing pollution in India though an engineer GeoGraphy and you Editor Sulagna Chattopadhyay LEgaL advisor KriShnendu datta rEsEarch pritiSha borthaKur covEr PhotograPh teChnologieS for the future- a neW World. baCKground: naSa sPonsorshiP forty eight pageS of thiS earth SCienCeS SpeCial have been SponSored by the miniStry of earth SCienCeS, neW delhi g’nY PhotograPhY praSad iris PubLication Pvt. Ltd. regiStered offiCe 111/9, aruna aSaf ali marg, KiShangarh, vaSant Kunj, neW delhi-110070. corrEsPondEncE/ EditoriaL officE 1584, b-1, vaSant Kunj, neW delhi-110070 phone: 011-26122789 for neW SubSCriptionS, reneWalS, enquirieS pleaSe ContaCt CirCulation manager e-mail: geographyandyou2001@ yahoo.co.uk pleaSe viSit our Site at www.geographyandyou.com for further information. ©iris PubLication Pvt. Ltd. all rightS reServed throughout the World. reproduCtion in any manner, part or Whole, iS prohibited. printed, publiShed and oWned by Sulagna Chattopadhyay.

PrintEd at india graphiC SyStemS pvt. ltd. f-23, oKhla induStrial area, phaSe-i, neW delhi - 110020.

PubLishEd at iriS publiCation pvt. ltd. geography and you doeS not taKe any reSponSibility for returning unSoliCited publiCation material. all diSputeS are SubjeCt to the exCluSive juriSdiCtion of Competent CourtS and forumS in delhi/neW delhi only.

by profession I have a keen interest in geography, specially geomorphology. Apart from bookish information I am always eager to grasp practical aspects through newspapers, journals, magazines etc. I read the June issue of Geography and You and instantly perceived its excellent quality and density of information about the current pollution scenario.

I want to thank the team for imparting intense knowledge to the masses through such content. Keep up the good work.

— Abhinav Kumar, BHEL, Ranipur, Haridwar

I enjoyed reading the June Issue of Geography and You. The cover story ‘Bloody Plastics’ is an interesting piece of work. Many questions came to my mind as I finished reading the article. Lack of proper disposal measures of sanitary napkins is indeed a serious concern that needs immediate attention.

I would want to know from our policy makers if manufacturing of biodegradable sanitary pads in our country could be the answer to stop using plastics in sanitary napkins. sAurAbh GAutAm Kanpur, Uttar Pradesh

I have recently come across the Geography and You magazine and am keen to subscribe it regularly.

The content of the magazine is very impressive and easy to understand.

As I am preparing for my civil service examination, it will be very useful in my preparation.

PrAshAnth s. chinnAPPAnAvAr Haryana

The June issue of Geography and You is really excellent. The information provided here is very

valuable and the factual presentation regarding pollution aspects in India is pertinent. I appreciate the GnY authorities for publishing such a fantastic issue. rAvi krishnA Paloncha, Andhra Pradesh

I am a regular reader of Geography and You. I really enjoy reading the travelogues published in the magazine and also online. I had seen an interesting article on Chau dance published earlier in one of the issues. I would also like to contribute a feature on idol making during Durga puja, the greatest festival of West Bengal. shreyA sikder West Bengal

I have recently subscribed to Geography and You and now I am a regular reader. The various subjects it covers are very useful and have helped me in preparing for my competitive exams. I appreciate the language, which is comfortable for all kinds of readers. shAkil hAq Bengaluru, Karnataka

Write Editorial Office: Geography and You, 1584, B-1, Vasant Kunj, New Delhi-110070, Letters may be edited for clarity and length. Include name, address and telephone. Phone 011-26122789, FAX 011-41775126, emAil geographyandyou2001@yahoo.co.uk, FAcebook http://goo.gl/eIeaH, linkedin http://in.linkedin.com/pub/geography-and-you/5a/b32/b24 Website www.geographyandyou.com.

To contribute an article. Kindly send the abstract of your article in not more than 200 words to geographyandyou2001@yahoo.co.uk. The abstract will be reviewed by our guest panelists. Once the abstract is selected we shall respond immediately for the full article. The length of the final article may range from 1200 to 1500 words. Please also mention if you can contribute relevant high resolution photographs. The Editorial Advisor GeoGraphy and you  july - auGust 2013  3

n ews Brief

Updates

India’s fragility arises from its need to protect its ever growing populace. In a changing climatic scenario where nature has turned maverick, we need newer technologies to outwit the downtrend.

Uttarakhand floods: GIC preparing ‘hazard map’ to identify disaster-prone areas 7 July 2013, IndIa Today

In the wake of the Uttarakhand floods, India’s national reinsurer General Insurance Corporation (GIC) said it is preparing a ‘hazard map’ to identify areas which are more prone to disasters.

The map will take around six months to prepare and once ready, could be used by insurance companies to assess their exposures in such areas and build the risks into their pricing. GIC has engaged an external research team, which is working with Indian Space Research Organisation (ISRO) to prepare the map. The company would insist on proper implementation of the codes for construction in the country’s disaster prone areas in order to avoid mass devastation.

“The premium for insuring properties in those areas may be higher and there could be a mechanism whereby insurance companies can refuse claims if insured entities don’t follow rules,” said a GIC official. The country’s general insurance industry was estimated to incur losses 4  july - august 2013  geography and you

to the tune of Rs. 3,000 to 4,000 crore against claim settlement towards 240odd damaged hydroelectric power projects in Uttarakhand following the unprecedented disaster.

‘Great earthquake’ likely to rock India, warns expert 2 May 2013, The new IndIan express

A great earthquake of magnitude greater than 8 on the Richter scale is likely to rock India in the next few years though the epicentre cannot be predicted, an expert warns. The Deccan Plateau and the southern region of the country, situated relatively in the middle of the plate, may witness an earthquake of maximum 6.5 magnitude, says R K Chadha, chief scientist (seismology) at the National Geophysical Research Institute. “The reason that there was greater loss due to even a 6.3 magnitude quake in Latur was the high population density in the region as compared to the Himalayan region,” he explains. The predictions are based on a periodicity of 15 year duration during which seismic activities are high. “Basing on the data of the last 100 years, eight

major quakes occurred between 1905 and 1920, a pattern which was repeated in the 1950-1965 period, including the world’s largest recorded earthquake of magnitude 9.5 in Chile. It has also been observed that since 2004 six great quakes have occurred globally. There is a likelihood that over the next five years another quake or two of magnitude greater than 8.5 will occur,” says Dr Chadha.

Andaman tsunami warning system can alert in 3 mins 12 June 2013, daIly news analysIs

The Early Tsunami Warning System installed at Rangachang in Andaman and Nicobar Islands can predict a tsunami immediately after an earthquake, chief scientist of National Institute of Ocean Technology, Vinith Kumar said. The system would assess the impact of waves during the earthquake for the possibility of triggering tsunami and send the alerts, he said. After that, tsunami alert would be issued to the risk zones by the Centre in consultation with Indian National Centre for Ocean Information Services at Hyderabad.

He also said that the Centre has installed 10 fish aggregating devices (FADs) in 10 locations across the islands, including Mayabandar, Dilgipur, Chidiayatapu, Hut Bay, Car Nicobar and Campbell Bay for the benefit of the fishermen.

These devices at the cost of Rs 10 lakh each have been designed and installed to improve the fish catch. An Islands Resource Information System (IRIS) has also been developed for better exploitation of the resources.

Desalination plant planned near Gopalpur in Odisha 6 May 2013, The TIMes of IndIa

A desalination plant that will convert seawater into potable one is being planned near Gopalpur in Ganjam district. The Indian Rare Earths Limited (IREL) has decided to install a 5 million litre per day (mld) capacity plant to meet the industrial and potable drinking water requirements for its Odisha Sands Complex (OSCOM) at Matikhala near Chhatrapur. The Rs 112.9 crore project is scheduled to be completed by March 31, 2019. Since water supply from all sources to Berhampur is not adequate, the town is reeling under acute shortage of drinking water, particularly during peak summer.

Global warming Vs volatile monsoons: World Bank 19 June 2013, MoneyconTrol.coM

India’s summer monsoon will become highly unpredictable if the world’s average temperature rises by 2 o C in the next two to three decades, says a scientific report, ‘Turn down the heat: Climate extremes, regional impacts and the case for resilience,’ commissioned by the World Bank. The Report released on 19 June 2013 evaluates the likely impacts of warming between 2 o and 4 o C on agricultural production, water resources, coastal ecosystems and cities across South Asia, sub-Saharan Africa and South East Asia. Coastal cities like Kolkata and Mumbai are ‘potential impact hotspots’ threatened by extreme river floods, more intense tropical cyclones, rising sea levels and very high temperatures, the Report says and warns that by the 2040s, India will see a significant reduction in crop yields because of extreme heat. geography and you  july - august 2013  5

l andslide prediction VIEW POINT

Vinod Tare

Department of Civil Engineering, Indian Institute of Technology, Kanpur vinod@iitk.ac.in

The 2013 Uttarakhand floods: Two faces of a disaster T

he himalayan regions of India are geologically fragile and highly eco-sensitive, and hence prone to certain types of natural disasters. Among the Himalayan states, Uttarakhand has been notable for a plethora of such disasters in recent decades, including floods and landslides in almost every monsoon season. Hence, except for the heavy toll of pilgrims and tourists and damages to shrines and property, the severity of the floods in June 2013 in Rudraprayag, Uttarkashi and Chamoli districts may not have attracted overwhelming attention. Indeed, the ravaging floods that occurred simultaneously in Pithoragarh district went almost unnoticed at first, which reinforces the notion that such floods are now considered almost normal in Uttarakhand. It is against this background that we briefly review the ‘hows’ and ‘whys’ of this disaster. But, at the outset, we would like to declare that our own expertise on the subject is limited. The problem is multi-faceted, and our understanding of it is grounded in the environmental studies of National Ganga River Basin (Uttarakhand state lies in this basin) that we have been conducting in the recent years. Natural disasters are ‘natural’, that is they are caused by natural forces beyond human control (and, often, beyond human understanding). But human activities can also affect the magnitudes of such disasters, either positively or negatively and sometimes they may even trigger such events. Hence, broadly speaking, the recent floods of Uttarakhand are a combination of both natural and manmade causes. natural Causes: The floods were essentially caused by heavy rainfall in Uttarakhand in mid-June, with the monsoon having entered the state about a fortnight earlier than usual. We look at the possible natural causes that may have accentuated the floods.

Early monsoon: The early onset of monsoon caught people unawares (hence causing significant damage to life and property), but there is no plausible reason for the earliness of monsoon to have intensified the floods.

6  july - august 2013  geography and you

Extreme rainfall event: High rainfall magnitudes are not very rare in Uttarakhand.

While we have not analysed the data, rainfall in the affected districts does not seem to have been so high as to suggest an exceptionally rare event.

Widespread rains: The rainfall events before and during the above floods occurred widely over the catchments of Alaknanda, Bhagirathi and other rivers, thereby sending high runoff into these rivers. But such widespread rains in these regions are also not as exceptional as the flood fury suggests.

Heavy rains at the start of monsoon: It seems to us that heavy rains rarely occur in Uttarakhand at the very start of monsoon. Usually, the rains are relatively light and scattered at first, before increasing in magnitude and spread after 2 or 3 weeks. In the present case, however, the monsoons entered the State with a bang, which may have been a factor that intensified the floods. This is because rains cause landslides/ landslips due to unstable slopes and loose rocks/boulders, which tend to (partially) block the stream paths; and when these blockages get blown away, the dammed up water disgorges with high flood peaks. Thus, whereas in previous years minor landslides would occur at the start of monsoon, and their blockages get dismantled before the onset of heavy rains, in the present case both minor and major landslides would have occurred simultaneously in mid-June, thereby producing dam-burst like floods. manmade Causes: Local anthropogenic factors were certainly a crucial reason for the devastating flood peaks. A large number of commentaries have highlighted several factors of significance - rampant deforestation, slope cutting, blasting of rocks, haphazard disposal of debris, and riverbank constructions. These activities invariably tend to enhance landslides (through weakened rock structures and soil stabilities), increase the runoff rates, and/or disrupt river flows. Such activities are largely related to extensive and growing pilgrimage and tourism in the State. But the increasing number of dams (and barrages) in the region is also considered by many to be a key factor. In our view, there is much confusion about dams. In our opinion dams do have significant adverse effects on river health, but they do not cause or accentuate floods by their mere existence (except when floodgates are operated irresponsibly). The conventional manner of constructing dams–involving rock blasting, careless disposal of debris, deforestation, etc.–may be major factors that promoted the high flood waves in Uttarakhand, but not the dams themselves. In fact, dams may actually provide safety against floods: the Managing Director of Uttarakhand Jal Vidyut Nigam Limited had in fact pointed out that Tehri Dam had actually absorbed the flood wave of Bhagirathi river on June 16th, thereby preventing downstream flood damage. end nOte: The remedies for the natural and manmade faces of disasters like the Uttarakhand floods are different in nature. Natural causes cannot be waived away, but we can prepare to face them. Thus, knowing that monsoons may set in vigorously in midJune, it may be prudent to remove tourists and valuable assets from hazard-prone regions by early June. And, in case of extreme natural events thereafter, locals can be alerted (and evacuated) at short notice through early warning systems. On the other hand, manmade causes are eminently preventable by adopting suitable preventive measures (plus remedial measures where needed). The complete strategy calls for an expert review of both types of problems and a consequent plan of action. We believe that the government has already embarked on such expert assessments and we hope that all issues will be reviewed with an open mind and wide consultations, taking account of factual data, people’s concerns, and the environmental and socio-economic realities of the region. geography and you  july - august 2013  7

l andslide prediction VIEW POINT

Rajiv Sinha

Department of Engineering Geosciences, Indian Institute of Technology, Kanpur rsinha@iitk.ac.in

The Alaknanda disaster: A result of ‘river space’ incursion T

he AlAknAndA disaster in Uttarakhand in northern India during 15-16 June 2013 is one of the worst human tragedies in recent history. The impact of this event has reminded us once more of the increased and undesirable human interventions on the natural systems. The trigger for this event was an unusual natural process–cloud burst at several locations bringing down 200-400 mm of rains during 13-19 June, followed by lake burst at a couple of glacier snouts such as the Chorabari glacier lying on the slope of the 6,940 m Kedarnath peak and the Milam glacier upstream of the Goriganga and the Kaliganga. Such phenomena are generally called glacial lake outburst flood (GLOF) and they do occur in glaciated regions at regular intervals. However, this event affected a large population living very close to the rivers, which were flooded suddenly at a time when a large number of pilgrims were en route to the Kedarnath temple. The impact of this event could have been easily minimised if we had a little more consideration and understanding of the river processes.

As a part of the Ganga River Basin Management Plan being prepared by the consortium of Indian Institutes of Technology, we submitted a report to the Ministry of Environment and Forests (MoEF) in December 2010, which proposed the concept of ‘river space’ for performing the natural and ecological functions of rivers. River space consists of the ‘floodplain’ and ‘valley margin’ of the river and its width on both sides of the river can be spatially variable depending upon geomorphic considerations. The active floodplain, hydrologically defined as the area inundated by 2.33 year (average theoretical return period) flood, is the ecologically most sensitive zone and supports a wide variety of vegetation and life forms; its complete preservation is one of the prime indicators of good river health. The human dimension of the river space is that

8  july - august 2013  geography and you

this zone should be kept free of habitations as much as possible not only from the river health viewpoint but also from a human risk perspective – a point well illustrated by the recent disaster.

Recognising the fact that “the anthropogenic pressure on ecosystems and environment has tremendously increased, causing irreparable damage to the fragile mountain ecosystems including flow and character of the river,” the MoEF issued a notification dated 18th December, 2012 declaring the 130 km stretch from Gaumukh to Uttarkashi in the Bhagirathi valley as an eco-sensitive zone strictly prohibiting large-scale settlements.

Unfortunately, this notification was never implemented by successive governments in Uttarakhand. Although this notification did not include the Alaknanda valley, which was affected most by the recent disaster, this was the first attempt towards identifying river space.

Had this been implemented and extended to other vulnerable areas in this region, it could have saved hundreds of lives. It is certainly desirable that we start a serious debate on defining river space and declaring this as a no-go zone.

Another related issue is the impact of the existing/under construction/proposed hydroelectric projects along the several tributaries of the Ganga in this region.

The claims of the governmental agencies that the existing dams (e.g. Tehri on the Bhagirathi) helped to reduce the impact downstream have been rubbished by the non-governmental agencies. In any case, the peak flow in the Alaknanda valley occurred later than in the Bhagirathi valley. There are also suggestions that peak flow at Rishikesh and Haridwar could have been earlier in the absence of Tehri Dam but not much higher than what was observed. On the other hand, several under construction hydroelectric projects on the Alaknanda such as at Vishnuprayag and Srinagar not only got severely damaged but probably created additional problems.

An important observation by many has been a huge pile of sediments deposited by the river in many areas and it is not clear if these sediments were derived from the hill slopes alone or a part of this was a result of severe degradation due to construction activities around the hydroelectric projects.

The final point is that a proper understanding of river processes must be emphasised in river management and development. The urban development around the Kedarnath temple close to the abandoned channel of the Mandakini river by a landslide a few decades ago reflects extreme ignorance of the ways the rivers work both by the administration and the local community. Such abandonment and reactivation of river channels are known to occur over decadal scales and the identification of such hazards related to river dynamics must figure prominently in the development plans of the mountainous areas close to rivers in a region, which is known to be one of the most fragile mountains in the world. geography and you  july - august 2013  9

L andslide prediction VIEW POINT

J SrinivaSan

Divecha Centre for Climate Change Indian Institute of Science, Bangalore jayes@caos.iisc.ernet.in

Advance warning system for Uttarakhand T

he extreme rainfall,floods and landslides that occurred in Uttarakhand during 16-18 June 2013 has caused unprecedented deaths and destruction of property. People have asked if we could have avoided the tragedy through an advanced warning system and enforcement of building laws. The phenomenon of extreme rainfall and floods occur all over the world but we do not see as many deaths as most countries have a good advance warning system. The consequence of extreme rainfall can be predicted accurately. A high resolution terrain data can be used to convert rainfall rate to flood levels at various points along the course of the river. For the purposes of flood prediction, the rainfall rate can be calculated based on cloud data from a geostationary satellite. In addition, rainfall prediction by weather forecast models, two to three days in advance, is adequate for flood prediction. Hence a warning about potential flood and landslides in Uttarakhand could have been given on the evening of 16th June 2013 based on the forecast available on the website of India Meteorological Department (IMD) on 15th June 2013. Such a warning could have saved thousands of lives in the Mandakini valley in Kedarnath. This was not done because of the mistaken belief that the rainfall predictions are not accurate and the remarkable improvements that have occurred in short-term rainfall forecasting during the past decade was not appreciated by the National Disaster Management Authority (NDMA). There are hundreds of automatic rain gauges in India which can be designed to send an alarm through the mobile network to any district official as soon as the rainfall rate exceeds a certain threshold. These actions do not cost much and can be implemented fairly quickly. In country that has hundreds of TV channels it is surprising that we do not have a channel devoted solely to weather, climate and extreme events. Such a channel would have increased awareness among our people

10  july - august 2013  geography and you

about the consequences of extreme rainfall in the Himalayas.

The destruction of a large number of buildings in Uttarakhand was on account of the gross violation of building laws.

The number of new buildings that have been permitted near the banks of the river during the past 20 years in Uttarakhand is astounding. In Kedarnath, there were few buildings around the temple 30 years ago.

The construction of a large number of ugly concrete structures around the temple not only destroyed the beautiful ambience of this valley but it also contributed directly to a large number of deaths that occurred as a consequence of debris slide. Ten years ago the Geological Survey of India (GSI) had pointed out that the area around the temple was vulnerable to landslides and suggested that the pilgrims should stay near the region where the present helipad is located. If this suggestion had been implemented, most pilgrims would not have succumbed to the debris slide that occurred on the morning of 17th June 2013. The threat of landslide is indeed large in Uttarakhand after heavy rainfall as most of the hills in the outer Himalaya are made of river debris. Most landslides occur during July and August when the rainfall in normally high. This year the heavy rainfall unexpectedly occurred in June.

There are simple methods available to predict the probability of landslide based on accumulated rainfall thresholds and these should have be used by NDMA to provide a map of ‘landslide threat’ on their website. They should have provided training to the travel agencies that bring pilgrims to Uttarakhand so that they unmistakably comprehended the threat. When you enter a mountainous region in developed countries there are clear warning signage on the road about possible avalanches and landslides along stretches. If such a practice existed in India, many tourists and pilgrims would have decided not to go beyond Rishikesh.

But could we have predicted the catastrophic debris slide that occurred on 17th June morning in Kedarnath on account of bursting of a lake? Perhaps one could have predicted that the probability of a flood was high but the precise prediction of debris slide would have been more difficult. This would have demanded the monitoring of high latitude lakes and associated landslides in the region. Since millions of pilgrims visit Uttarakhand each year it may be necessary in future to monitor few of the lakes that pose a direct threat to the four valleys visited. There is an urgent need to establish an institution that can provide maps of regions prone to landslide threat after a heavy rainfall episode. Such institutions exist in many Asian countries. And as fragile as Uttarakhand is, with a double threat from both earthquakes and extreme rainfall—it is absolutely imperative that an advance warning system may be established here as soon as possible. geography and you  july - august 2013  11

E arth science technologies

N Chattopadhyay and L S Rathore

Extreme Events

Weather Service for Indian Agriculture 12  july - august 2013  geography and you

PHOTO COURTESY: NASA

In the recent past escalating extreme weather events are causing concern in the different sectors of the Indian economy, especially agriculture. Weather and climate information plays a significant role in minimising crop losses and the India Meteorological Department (IMD) is dedicatedly providing advance information and advisories to the farming community. geography and you  july - august 2013  13

T

he term extreme weather or climate event refers to ‘an occurrence of...a weather or climate variable beyond a threshold...,’ Intergovernmental Panel on Climate Change, (IPCC) 2012. It includes very high (and low) temperatures, very heavy rainfall (and snowfall in cold climates) and very high wind speeds.

By definition, extreme weather events occur only rarely and are noticeable as they are so very different from the usual (Fig 1). They are however, associated with adverse impacts on humans, infrastructure and ecosystems. In many cases, the most severe impacts are felt when several extreme events occur simultaneously. Examples include: (i) the impacts on agriculture when a combination of drought and a heat wave occur; and (ii) high bush fire danger weather, which can be a combination of high temperature, low humidity, high wind and drought.

Indian agriculture and extreme weather events: The challenges facing agriculture in India are ever increasing. In the present global climate change debate the sustainability of intensive agriculture using current technologies is being questioned. Long-term changes and the increasing frequency of extreme weather events are likely to adversely impact the agricultural sector. Recurring failure of rains and occurrence of natural disasters such as floods and droughts could lead to crop failures, food insecurity, famine, loss of property and life, mass migration, and negative national economic growth.

The 2001–2010 decade witnessed the intensification of climate and weather extremes such as destructive flooding, severe droughts, heat waves, heavy downpour and severe storms. The number of extreme events of rainfall (very heavy rainfall) has almost doubled in the country in the last 50 years

16 14 12 10 8 6 4 2 0

1950

1955

Flood Storm

1960

1965

1970

1975

1980

1985

1990

1995

2000

2005

Earthquake/tsunami,volcanic eruption Others (heat wave, cold wave, forest fire)

Fig 1: Trends of extreme weather events in India

and the observed trends suggest enhanced risks associated with extreme rainfall over India in the coming decades.

Trends of extreme weather events in India: With respect to cyclones, India is particularly vulnerable because of its relatively large percentage of the population living in coastal districts that lie in the path of cyclones.

Climate information and loss minimisation: Beyond doubt, climate information services will be one of the tools to meet the challenges of the future particularly with reference to extreme events. The provision of need-based climate information to farmers can support the management of agricultural resources (land, water and genetic resources).

Better understanding of climate in a location provides opportunities to design various measures to reduce its impact on natural resources. Climate information services are needed for landuse planning, agroecological zoning, sustainable land and forest management. Recent improvements in the provision of advance climate information allow the

Farmer Awareness Programme

Initiated by the India Meteorological Department (IMD) in collaboration with Agromet Field Units (AMFUs) and arranged in 104 locations over different districts in the country till now, the programme improves linkages with the Agrometeorological Advisory Services and develops a local rain measuring network. A group of progressive farmers are selected and trained by the AMFUs during meetings and the records are communicated to the IMD.

16

Fig 2: Standard Precipitation Index (SPI)

15 14

12 13

2 11

17

18

5

10 9

SPI Criteria 2.00 or More extremely Wet (eW) 1.50 to 1.99 Severely Wet (SW) 1.00 to 1.49 Moderately Wet (MoW) 0 to 0.99 Mildly Wet (MIW) 0 to -0.99 Mildly Dry (MID) -1.00 to -1.49 Moderately Dry (MoD) -1.50 to -1.99 Severely Dry (SD) -2 or LeSS extremely Dry (eD)

20

21

22

8

19

3 4

6

27 26 23

24

7

25 29 28

33 30

32 34

1

36 Standard Precipitation Index (SPI), June+July+August+September 2012 Source: IMD

earliest identification of areas likely to be affected by a specific climate risk.

Drought monitoring: In the case of drought, for example, a combination of traditional and more innovative technological approaches are being used to manage risks. Technological drought management (e.g. development and use of drought tolerant cultivars, shifting cropping seasons in agriculture, and flood and drought control techniques in water management) is combined with model-based seasonal and annual to decadal forecasts. Model results are then translated into an early warning in order to take appropriate drought protection measures.

Aridity anomaly index is used to monitor the incidence, spread, intensification and recession of drought. With the help of aridity anomalies, crop stress conditions in various parts of the country is monitored during the monsoon season. These anomalies are used for crop planning and in the early warning system during drought/desertification. The Standard Precipitation Index (SPI) is a relatively new drought index based only on

31 35

1-36 : Meteorological sub-divisions Map not to scale

precipitation (Fig 2). Its an index based on the probability of precipitation for any time scale.

Depending on SPI values and categories of rainfall situation, drought condition for a particular period is determined. Along with the prediction of cyclonic storms issued by the Cyclone Warning Division of India Meteorological Department (IMD), during ‘THANE’ and ‘NILAM’, Agromet Field Unit simultaneously issues Special Agromet Advisory Bulletin for fisheries, animal husbandry and horticulture crops.

Forecast for extreme events: Special weather forecast for agriculture provides the necessary meteorological input to assist farmers in making decisions. The requirements for these special forecasts will vary from season to season and from crop to crop and are normally issued for planting, chemical application, forestry etc. Special extreme event forecast issued are as follows: n Tropical cyclone (North Indian Ocean) track, intensity, structure changes and landfall process (wind and gust, rainfall and storm surge); n Heavy rain and strong winds triggered by tropigeography and you  july - august 2013  15

Banana trees damaged by heavy rain and uprooted by high winds in tamil nadu and Kerala, april 2011.

Source: Regional Meteorological Centre, Chennai, IMD

cal cyclones, SW and NE monsoon, troughs and ITCZ migration and orography; n Thunderstorms and hail associated with severe convection; and, n Extreme hot and cold conditions and frost.

The IMD is operating an Integrated Agro-Meteorological Advisory Services (IAAS) at the district level in India—a small step towards agriculture management in rhythm with weather and climate variability, leading to weather proofing for farm production. The network for assessing extreme events in the nation includes the conventional observational network, automatic weather stations (AWS), buoys/ship observations, cyclone detection radars, Doppler weather radars and satellites observations. Satellite and radar observations are very crucial for the assessment of hazards, especially in the Himalayan region and the North Indian Ocean.

Under IAAS, IMD has started issuing quantitative district level weather forecast upto 5 days from June, 2008. In the current plan period IMD is venturing into block level forecast.

16  july - august 2013  geography and you

The IAAS is also disseminating advice to the Indian farming community through SMS messaging and Interactive Voice Response Technology (IVR). In a public-private partnership arrangement, AMFUs are preparing and sending district AAS bulletins twice weekly to private companies including IFFCO, Kisan Sanchar Limited (IKSL), NOKIA, Reuter Market Light, Handygo, state department of agriculture and comprising weather forecasts and advisory on extreme events along with crop, pest, disease, seed and fertilizer information. Sixteen states (Delhi, Uttar Pradesh, Punjab, Haryana, Rajasthan, Madhya Pradesh, Odisha, West Bengal, Gujarat, Karnataka, Kerala, Tamilnadu, Andhra Pradesh, Bihar, Maharashtra and Himachal Pradesh) have been covered by this service, with around 3 million farmers receiving updates and advisories.

The authors are deputy director general, Agricultural Meteorological Division and director general at India Meteorological Department, respectively. ls.rathore@imd.gov.in

Term Power

Answers on PAge 29 ❯❯

Mandakini river

Tilwara

Land slump

Here are some sliding terms that are waiting for you to jump away to avoid collision—get the right answer before you are pulled down under. See page 29 to check whether you made it or not.

RAIN FACT Intense rainfall spanning several days starting from the 15th of June 2013 centered on the north Indian state of Uttarakhand caused devastating floods and landslides. According to figures provided by the Uttarakhand government, more than 5,700 people were 'presumed dead'. Photo: NASA

1. Mass wasting

a. Bulk movement of soil and debris down a slope b. The total waste produced by urban inhabitants in a day c. The reduction of total mass of a glacier as it moves downslope.

2. Lahar

a. A relatively low tsunami wave b.

A debris flow consisting of volcanic material and water c. A thick layer of ash deposited on water surfaces near volcanoes.

3. Regolith

a. Loose unconsolidated rock and dust which forms a layer, resting on the bedrock b. A type of intrusive volcanic structure c. An archeological term used to define fossilized remains of plants.

4. Scarp

a. A steep slope exposed due to displacement of material in the form of a landslide b. The

mound of accumulated debris of a landslide c. The steep edge of a mountain.

5. Flood fringe

a. The edge of a flooded area where the flood water is retreating b. A part of the flood plain adjacent to the floodway c. It is that period of time when the flood is retreating.

6. Break in monsoon

a. The period of break between the south-west monsoons and the onset of the north east monsoons b. Spells of sparse rainfall during the mid monsoon months of July and August c. Withdrawal of the monsoon winds.

7. Flood proofing

a. A combination of structural and non structural adjustments made to protect buildings from flood damage b. Use of only check dams and levees to control flooding c. Barricading each

house to prevent flood water from entering.

8. Solifluction

a. Excessive water saturation in soil leading to decrease in agricultural productivity over time b. Accumulation of toxic chemicals in soil due to incessant fertilizer usage c. Slow flowage of water saturated soil down a slope.

9. Hummocky toe

a. Layers of mounds of debris at the foot of a landslide b. The protruding edge of a hanging rock after a landslide has taken place c. A type of depositional glacial moraine after the glacier has retreated.

10. Scree slope

a. Loose rocks and debris covering a slope, formed due to agents of weathering b. The slope formed by the movement of a glacier c. The route taken by a mudflow.

GeoGraphy and you  july- auGust 2013  17

E arth

s c i e n c e t ec h n o l o g i e s

IllustratIon of a satellIte recordIng observatIons Photo courtesy: nasa

18  july - august 2013  geography and you

Remote Sensing Applications This article provides glimpses of work related to remote sensing applications for earth sciences carried out at Space Applications Centre, Ahmedabad jointly with a large number of institutions in the country.

J S Parihar, a S raJawat and PrakaSh Chauhan

geography and you  july - august 2013  19

R

emote sensing primarily involves interpretation and analysis of electromagnetic radiations interacting with earth and its atmosphere utilising data collected by earth observation (EO) sensors onboard aerial or satellite platforms. The EO system with its ability for a synoptic view, repetitive observations at different spatial, spectral and radiometric resolutions has been widely accepted as an indispensable tool for natural resources inventory, monitoring, generating data for resource management planning, weather forecast, disaster damage assessment and climate change studies. The Indian Earth Observation Programme has been applications driven and contribution to national development has been its prime motivation. India’s EO capability has increased manifold since the launch of experimental satellite Bhaskara-I in 1979 to the recent launches of RISAT-1 in April 2012, Saral AltiKa in March 2013 and INSAT-3D in July 2013. The improvements in observation capabilities are not only in spatial, spectral, temporal and radiometric resolutions, but also in their global coverage as well as value-added products.

EO data has been extensively used in a number of earth science applications for societal benefits; and studies have been carried out at Space Applications Centre (SAC), Ahmedabad, involving scientific teams from institutions specialising in various fields of applications. Many of the projects have been sponsored by Ministry of Environment and Forests, Ministry of Water Resources and have been carried out in collaboration with Ministry of Earth Sciences. This article provides a glimpse of such work.

Applications in Earth Sciences

Monitoring Snow and Glaciers of Himalayas: Remote sensing and GIS based techniques along with field expeditions have been developed to map and monitor snow and glaciers of the Himalayas.

Glacier inventory was carried out for the Indus, the Ganga and the Brahmaputra river basins on 1:50,000 scale using images of Indian remote sensing satellite for the period 2004-2007 and a database has been prepared in a geographic information system (GIS) environment. Fig 1 shows typical glacier features like accumulation area, ablation zone, snow line, snout, glacier lake in Himalayan glaciated terrain as seen on IRS LISS-IV FCC image. The study has shown that 20  july - august 2013  Geography and You

there are 32392 glaciers covering 71182 sq km area in the Himalayan region. Normalised Difference Snow Index (NDSI) algorithm was developed using AWiFS data and continuous monitoring of snow cover of the entire Himalayan region at basin and sub-basin level is being carried out since the year 2004 at 10 day intervals by generating snow cover maps, carrying out area estimates and analysing the data. Glacier retreat/advancement has been monitored using temporal satellite images.

Monitoring of ~1800 glaciers in various parts of the Himalaya has indicated 17 per cent loss in glaciated area for the 1962-2001 time frame. It is also observed that ~2 per cent loss in glaciated area has occurred for ~480 glaciers monitored using satellite images from 1990 to 2001. Further it is also observed that for ~2000 glaciers monitored using satellite data of 2001-2011 time frame, there is < 0.2 per cent loss in glaciated area and 87 per cent of glaciers are observed to be stable. Techniques have been developed to estimate glacier mass balance.

The results are being utilised to understand the variability and effect of changing climate on snow and glaciers, estimating the snow melt runoff and hydropower potential for selected watersheds in the Himalayan region.

Desertification Status Inventory: Desertification is the process of land degradation in arid, semiarid and dry-subhumid areas. Desertification and land degradation status mapping has been carried out for the entire country on 1:500,000 scale using the AWiFS data. The dominant processes of land degradation, viz. water erosion, vegetal degradation, wind erosion, salinisation/alkalisation, water logging, frost heaving, frost shattering, mass movement, etc. have been deciphered and mapped using satellite data. The study reveals that 105.48 m ha area of the country is undergoing processes of land degradation (32.07 per cent of the total geographic area of the country). Area undergoing desertification is 81.4 m ha. Updation of desertification status maps has been taken up using recent satellite data sets.

National Wetland Inventory: Conservation and wise use of wetlands has been given priority world over. India harbours diverse types of wetlands.

National-level inventory and assessment of wetlands has been carried out using Resourcesat-1 LISS-III data of 2006–07 at 1:50,000 scale. A hierarchical system comprising 19 classes based on Ramsar definition has been used to classify the wetlands of India. The extent of wetlands has

been estimated to be 15.26 m ha. Inland wetlands account for 69.22 per cent (10.564 m ha), whereas the coastal wetlands account for 27.13 per cent (4.14 m ha). The high-altitude wetlands (situated > 3000 m asl) in the Himalayan states were also mapped, comprising 126,249 ha of areal extent.

The status of wetlands in terms of water spread, turbidity of open water and aquatic vegetation has shown significant variation during pre- and postmonsoon seasons.

Monitoring Indian Coastal Zone: Indian coast has been monitored using EO satellites for last three decades. Under these studies, methodologies have been evolved to study the coast using satellite data, generate baseline data, map the critical and vital habitats (coral reefs and mangroves), etc. Recently coastal landuse maps showing ecologically sensitive areas (ESAs) and high tide and low tide lines on 1:25, 000 scale using LISS-IV data of 2004-06 have been prepared and put in GIS mode. Coastal Zone Information System (CZIS) has been developed which includes baseline thematic data generated so far for all the maritime states and union territories of India. Shoreline change mapping of the entire Indian coast on 1:25,000 scale using satellite data of 1989-91 and 2004-06 time frame is completed and an atlas has been prepared showing areas under erosion and accretion and status of coastal protection works in an GIS environment.

The coastal thematic information derived from EO satellites and put in GIS environment as CZIS is widely utilised for several applications such as zoning the coast, based on Coastal Regulation Zone (CRZ) or Coastal Management Zone (CMZ) and in particular identifying ecologically sensitive areas, monitoring implementation of CRZ, site selection of mangroves and shelter belts, conservation of coral reefs and mangroves, site selection of any developmental activities, identification of eroding coast, understanding coastal processes, understanding the role of keystone coastal ecosystems in global climate change and identifying vulnerable zones due to predicted sea level rise etc.

Marine Lithosphere: Gravity, geoid and magnetic data provide the unique opportunity of seeing below water and thick sediments to understand the structure and dynamics of the Indian Ocean lithosphere. Altimeter derived geoid undulation and free-air gravity anomalies over oceans are important data to understand plate tectonic processes relating to oceanic ridges, subduction zones, formation of marine sedimentary basins and the

Glacier Features Snout

Ablation area

Accumulation areas Snow line

Fig 1: Irs lIss-Iv fcc (26 aug 2008) showing typical glacier features like accumulation area, ablation zone, snow line, snout and glacier lake in the himalayan glaciated terrain of Zanskar basin, Jammu & Kashmir.

evolution of continental margins. Geoid-topography and gravity anomaly-topography relations in spectral domain have been used to understand long-term mechanical properties of oceanic lithosphere under seamounts, oceanic ridges, fracture zones and subduction zones.

Techniques for the retrieval of geoid and gravity anomaly data from satellite altimetry and generate improved high resolution (1´×1´) geoid and gravity anomaly maps (accuracy~5 to 7 m Gal) of the northern Indian Ocean have been developed (Fig 2). Further, the geoid and gravity data have been utilised to understand the deep structure and evolution of Indian Ocean lithosphere and associated geodynamics. SAC is currently working towards further improvements in the geoid and gravity retrieval using Saral AltiKa data.

Early Warning of Disasters: Research and development activities related to developing techniques for early warning of some of the disasters under Disaster Management Support Programme (DMSP) of Department of Space have been taken up. Real-time cyclone track prediction algorithms using INSAT data have been developed and predicted in real-time with a lead time of 48 hours. Prediction of cyclone track and landfall has been made operational and technology has been transferred to India Meteorological Department (IMD). Technique was developed to detect cyclogenesis over the Indian Ocean based on pattern matching and use of OSCAT winds; and for autogeography and you  july - august 2013  21

m Ga

25o

50 200

Fig 2: high resolution (1’ x 1’) gravity anomaly map of the northern Indian ocean from satellite altimeter data (accuracy ~ 5-7 m gal. gravity anomalies for three different tectonic settings; a: continental margin (bombay high); b: Mid oceanic ridge system (central Indian ridge); c: aseismic ridge (ninetyeast ridge) are shown separately.

0

150

-50

-100

100

-150 50 -200 00 050

A

B

mated estimation of cyclone position and intensity using INSAT imager data. An operational webserver ‘SCORPIO’, for real time monitoring and prediction of cyclones is developed.

Early warning research towards identification of precursors to earthquakes has been taken up.

Earthquake precursors such as sudden rise in land surface temperature, crustal deformation changes, ionospheric perturbations have been studied for selected seismically active regions. Methodology for assessing coastal vulnerability to storm surges and tsunami are developed and demonstrated for Andhra Pradesh and Tamil Nadu coasts. Rainfall threshold based early warning models of landslides in Sikkim Himalayas have been developed.

For geospatial data generation and dissemination SAC has been analysing EO data from a host of sensors (e.g., hyperspectral spectrometers, altimeters, scatterometers, radiometers, imagers, sounders, synthetic aperture radars) along with a large number of partner institutes and generating geophysical and bio-physical data products useful for understanding and modelling various earth system science applications. This has led to demonstration of newer applications as well capacity building in the country.

Meteorological and Oceanographic Satellite Data Archival Centre (MOSDAC) is established 22  july - august 2013  geography and you

C

by SAC as a single window interface (www.mosdac.gov.in) to provide satellite and in-situ data and value added products to the scientific community in the fields of meteorology and oceanographyand earth sciences for their research work.

Way Forward

In order to cater to the needs of societal applications there is requirement for development of new sensors as well as run a continuity in the existing missions. A constellation of satellites is required for early warning of disasters. The new EO systems planned for launch in the near future are GISAT and INSAT-3D(R) missions. The need of the hour is to work on process models considering Earth as an integrated system. The concept of Earth System Science needs to be strengthened and space based observations needs to be integrated with numerical process models. The inter-institutional partnership has been developed as a part of work carried out so far, it will enable such an effort.

The authors are deputy director, Earth, Atmosphere, Ocean, Planetary Sciences and Applications Area (EPSA), head, Geosciences Division, and head, Planetary Sciences and Marine Biology Division, respectively, at Space Applications Centre (SAC), Indian Space Research Organisation (ISRO), Ahmedabad. jsparihar@sac.isro.gov.in

E arTh sCIenCe TeChnologIes

OzOne Column In India The stratosphere, a region above the weather producing layer—troposphere contains around 90 per cent of the earth's ozone. Depletion of this stratospheric ozone leads to deleterious environmental effects, thus necessitating continuous monitoring. The ozone column above the Indian subcontinent has been examined since 1970 and measurements show that although the total ozone content has not changed significantly—there has been a small reduction in stratospheric ozone and a substantial increase in tropospheric (surface) ozone. The transit time of ozone depleting chemicals from the earth’s surface to the stratosphere in the tropics is normally three to five years—however, since the life time of these gases in the stratosphere varies from a few years to hundreds of years, despite reduced or eliminated use of many CFCs their impact from the past may be affecting the ozone layer at present.

Contributed by Nandita Ganguly, associate professor, Department of Physics, St. Xavier’s College, Ahmedabad. ganguly.nandita@gmail.com

SUNRISE OVER THE PACIFIC PHOTO COURTESY: NASA

GeoGraphy and you  march - april 2013  23

E arth science technologies

TRADITIONAL FISH FARMING ALONG THE SOUTH INDIAN COAST

24  july - august 2013  geography and you

Farming the

SeaS

With maximum sustainable yield in capture fisheries achieved, technological innovations to increase yields seem imperative. In a recent breakthrough cages that can withstand turbulent seas have been developed by National Institute of Ocean Technology. The organisation is also involving the fisher community of Olaikuda for a large scale culture.

R Kirubagaran and M A Atmanand

geography and you ď&#x201A;§ july - august 2013 ď&#x201A;§ 25

T

he protein

requirement of an average individual is estimated as 0.72g/kg/ day (Institute of Medicine of the National Academies IMNA, 2005) which works out to 13.14 kg for a 50 kg person/year.

Hence the country’s current protein requirement to feed its 1.27 billion populations is approximately 16.69 mmt. With one third of the Indian population preferring a vegetarian diet and considering that the protein requirement of 60 per cent of its non-vegetarian population is also met by plant resources, the animal protein requirement of the country is estimated to be 4.45 mmt. To achieve the world’s average fish protein contribution of 16 per cent (Central Statistical Organization - Manual on Fishery Statistics, Ministry of Statistics and programme implementation CSO-MFS, 2011) in the total animal protein production (4.45 mmt) we need to generate 0.71 mmt of fish protein in our country. Bearing in mind the average protein content of fish (15 to 30 g /kg), to meet the present protein requirement of the nation we need to produce 31.64 mmt of fish against the current 8.8 mmt production. The country’s marine capture fishery has attained its maximum sustainable yield of 3.97 mmt out of the estimated fishery potential of about 4 mmt and there is no further scope to increase its productivity (Table 1). It is estimated

by Food and Agriculture Organization (FAO) that around 20 per cent of the total fish production of the world comes from capture-based aquaculture and that this practice needs to be encouraged and regulated for sustainable fish production (The State of World Fisheries and Aquaculture SOFIA, 2012).

However, fresh and brackish water culture has its own limitations and cannot be expanded beyond a certain level without harming the environment.

The only possibility to meet the present demand is by farming in the seas with recent technologies for which India is yet to frame its sea leasing policy.

The production of farmed aquatic organisms in caged enclosures has been a relatively recent aquaculture innovation. The cage aquaculture sector has grown rapidly during the past 20 years and is presently undergoing changes in response to pressures from globalization and growing demand for aquatic products in both developing and developed countries (Table 2). The opportunities for cage culture to provide fish for the world’s growing 26  july - august 2013  Geography and You

population are enormous, and particularly so in marine waters.

In the last three decades (1980–2010), world food fish production by aquaculture has expanded 12 times over, at an average annual rate of 8.8 per cent and Indian aquaculture has demonstrated a six and half fold growth over the last two decades, with freshwater aquaculture contributing over 95 per cent of the total aquaculture production (G. Syda Rao, 2009 ‘Overview on mariculture and the opportunities and challenges of cage culture in India’, National Fisheries Development Board).

The need to improve fish production capabilities of the country which is bestowed with 8,129 km long coast line, 2.02 million sq. km of exclusive economic zone (EEZ) and 5.3 lakh sq.km of continental shelf is very convincing. Despite the huge potential, the development of large scale mariculture in the country is yet to kick off. The major barriers in offshore farming are—lack of sturdy cages and anchoring protocols to withstand turbulent open seas; commercial production of marine finfish seeds; lack of nursery rearing sysTable 1. Fishery resources of India

Coastline

8,129 km

Exclusive economic zone

2.02 million sq km

Continental shelf

0.531 million sq km

Rivers and canals

173287 km

Swamps and wetlands

1097787 ha

Food plain and lakes

202213 ha

Upland lakes

72000 ha

Reservoirs

3153366 ha

Freshwater ponds

2254000 ha

Mangroves

356500 ha

Brackishwater ponds

1235000 ha

Estuaries

285000 ha

Lagoons

190500 ha

Per capita fish availability

9.0 kg/year

Present total fish production

8.8 mmt

Total capture fisheries

4.3 mmt

Total aquaculture production

4.5 mmt

Production / active fisherman (marine)

2,656 kg/year

Fish eating population

846 million

Source NIOT-2013

The opporTuniTies for cage culTure To provide fish for The world’s growing populaTion are enormous, parTicularly in marine waTers. tems to supply stockable size seeds for open sea cage culture; availability of formulated species specific feeds; and above all legislative support for fish culture in the sea.

The National Institute of Ocean Technology (NIOT), with expertise in marine engineering and biology decided to address the prime issue of designing a culture system for mariculture operation both at nearshore and offshore areas along with standardization of mooring configurations. While appreciating the vastness of the Indian seas and its ideal tropical climate for fish farming, the rough sea conditions, high water currents, absence of shore landing facilities are points to ponder when designing sea cages. Taking into considerations the nuances of sea farming, the Institute has custom designed high-density polyethylene (HDPE) cages (9 m in diameter) and fabricated and deployed them with multipoint mooring system in three different environments that represent the country’s prime marine ecosystems. These cages are presently being tested with various marine finfish species obtained from hatcheries as well as from the wild.

Though the cages developed could withstand the sea conditions during the last 3 years of deployment, accessing these cages in rough weather with no shore landing facility or jetty was difficult.

Hence, the need for automated cage with shore control facility arose in order to ensure year round culture. There is no established system for taking care of nursery rearing in a large scale to provide stockable size fish seeds. The infrastructure available for fish seed production are insufficient when compared to the country’s huge requirement and out of the 80+ species of marine finfishes standardised worldwide for aquaculture, we are limited to a single species (Lates calcarifer) with a production capability of mere 5 million fry/year.

As part of the cage development initiatives, NIOT has designed and developed a sea nursery cage with a diameter of 2 m for rearing 5 g size marine finfishes and demonstrated the nursery rearing of seabass fingerlings of 5-6 g to 30 g size with 90 per cent survival in 45-50 days both at Kothachathram (Andhra Pradesh) and Olaikuda (Tamil Nadu) in

Table 2. Top ten marine and brackishwater cage aquaculture countries Quantity (tonnes)

Country

pEr CEnt of total

Norway

652306

27.5

Chile

588060

24.8

China

287301

12.1

Japan

268921

11.3

United Kingdom

131481

5.5

Canada

98441

4.2

Greece

76212

3.2

Turkey

68173

2.9

Republic of Korea

31895

1.3

Denmark

31192

1.3

Source: Halwart and Arthur (FAO), 2007

open sea conditions. The cages will greatly reduce the difficulty in getting the stockable size fish seeds and transporting the bigger fish seeds to the sea cages. Further, the infrastructure requirement for a land based nursery rearing facility for rearing a million fish seed is estimated as 20,000 m3 of constructed area (a stocking density 50/m3) which can also be avoided.

To produce 1 mmt of marine finfish we need to establish industries for the production of 1,00,000 grow out cages with 400 cu m cultivable area and 3,00,000 units of nursery cages. Hatcheries should be established for the production of 1,500 million seeds of 5 g size with different finfish species suitable for the Indian seas. Fish feed industries should be created with the capacity of 1.5 mmt including 0.02 mmt of nursery feed production units. We also require allied fishery industries for fish processing and storage apart from scientific and skilled manpower. Above all, it is mandatory to have a sea leasing policy in place to ensure the safety of the cultured products in the sea, which may also motivate private entrepreneurs to venture into sea farming. The state governments may demarcate certain zones for sea farming activities after conducting a feasibility survey. geography and you  july - august 2013  27

Fig. 1: Cage culture of milkfish with seeds from the vicinity was initiated by Dr Shailesh Nayak, Secretary MoES on 25th June, 2013 at Olaikuda fishing village. The cage culture demonstration empowered the traditional fishermen of Olaikuda and Kothachathram with hands-on training in various aspects of cage farming including cage fabrication, deployment, net maintenance, seed stocking, feeding, disease control measures, harvesting, etc. This capacity building in cage farming may help generate alternative livelihood strategies.

Out of the more than 200 commercial marine food fishes available in the country, only few species are being attempted for hatchery production and only Lates calcarifer is being produced on a commercial scale by the Rajiv Gandhi Centre for Aquaculture and the Central Institute of Brackishwater Aquaculture. To initiate large scale fish production a country-wide survey needs to be initiated to know the seasonal seed availability of potential species. NIOT conducted a local survey around Rameswaram to take stock of the milkfish seed availability and found that along with mullets it was abundant around the Gulf of Mannar region between March and August (Fig.1). The region is also bestowed with rabbit and parrot fish seeds; rearing them in sea cages yielded encouraging results.

Despite the lack of reliable statistical information of cage aquaculture globally, a growing trend is evident in the segment. Brackishwater and marine cage farming is relatively new in Asia, having de28  july - august 2013  geography and you

veloped first in Japan for the Japanese amperjack (Seriola quinqueradiata). Over the last two decades, marine finfish aquaculture, predominantly cage farming, has spread throughout Asia with China and Vietnam mostly relying on wild collection for fish seed and feed (S S De Silva, et.al., (2007) ‘A review of cage aquaculture: Asia (excluding China)’, Cage aquaculture-Regional reviews and Global overview, FAO Fisheries Technical Paper) Considering the advancements that cage culture has made in countries such as Norway and Chile in terms of reduced antibiotics usage and prevention of feed loss, with improved feeds and feeding techniques, there is a possibility that this sector will contribute significantly to the protein needs of the world’s growing population. Developing sea farming or cage culture is thus a long term strategy.

The authors are the group head, Ocean Science and Technology for Islands , and the director, respectively, at National Institute of Ocean Technology, Chennai. kiruba@niot.res.in

Term Power raTing

Land Slump

■ 1 to 5 Correct - Informed ■ 6 to 7 Correct - Knowledge bank ■ 9 to 10 Correct - Encyclopaedia

1. Mass wasting

Ans. a: A geomorphic process whereby bulk movement of soil and debris occur down a slope, under the force of gravity.

2. Lahar

Ans. b: A debris flow consisting of volcanic material and water. These lethal mixtures of water and tephra have the consistency of wet concrete, yet they can flow down the slopes of volcanoes or down river valleys at rapid speeds, similar to fast-moving streams of water.

3. Regolith

Ans. a: Loose unconsolidated rock and dust which forms a layer, resting on the bedrock.

4. Scarp

Ans. a: A steep slope exposed due to displacement of material in the form of a landslide.

5. Flood fringe

Ans. b: A part of the flood plain adjacent to the floodway.

6. Break in monsoon

Ans. b: Spells of sparse rainfall during the mid monsoon months of July and August.

7. Flood proofing

Ans. a: A combination of structural and non structural adjustments made to protect buildings from flood damage.

8. Solifluction

Ans. c: Slow flowage of water saturated soil down a slope. Solifluction describes the slow downslope movement of water-saturated sediment due to recurrent freezing and thawing of the ground, affected by gravity.

9. Hummocky toe

Ans. a: Layers of mounds of debris at the foot of a landslide.

Researchers at the University of California, United States, have developed a model using satellite data on rainfall, topographical features of slopes, and land cover—and by testing the model on a dataset of previous landslides it predicts these historical events reliably. This could be the basis of a real-time, global landslide prediction system. —19 July 2013, www.scidev.net.

10. Scree slope

Ans. a: Loose rocks and debris covering a slope.

Landforms associated with these materials are often called talus deposits. Formation of scree or talus deposits results from physical and chemical weathering and erosional processes acting on a rock face.

GeoGraphy and you  july - auGust 2013  29

E arth

s c i e n c e t ec h n o l o g i e s

Calculating carbon uptake by the oceans

R Ramesh

30 ď&#x201A;§ july - august 2013 ď&#x201A;§ geography and you

Nitrogen-15 is an isotope that is useful in determining how much of the anthropogenic carbon dumped in the atmosphere is taken up by the oceans. Our efforts in the Indian Ocean to determine this rate is outlined here.

I

MeMbers of Physical research laboratory, ahMedabad undertaking exPeriMents in the southern seas

ncrease in the atmospheric CO2 due to fossil fuel usage, change in agricultural practices and deforestation is balanced by draw down by the land and ocean biota. About 104.9 Pg (1 Petagram = 1 Gigaton= 1015 grams) of carbon is fixed per year by the global biota, out of which about 46.2 per cent (48.5 Pg) is taken up by the oceans alone. Here we show how the Nitrogen-15 (15N) tracer technique can be used to quantify this export flux of carbon into the deep sea.

The Indian Ocean has been identified as a net sink for atmospheric CO2. It takes up nearly 330430 Tg (tetragram) C (carbon)/year by solubility, accounting for nearly 20 per cent of the global oceanic uptake of CO2. Most of this air-to-sea CO2 flux is temperature driven and occurs south of 20ºS, after this latitude, the sea surface temperature decreases drastically. In contrast, the northern Indian Ocean (north of 35ºS) has been recognised as a net source of CO2 to the atmosphere; with an estimated outward flux of nearly 240 Tg C/year. Biological uptake of CO2 by the Indian Ocean has been estimated to be ~7501320 Tg C /year. Proposed estimates of CO2 loss from the warmer northern Indian Ocean range from 150 to 500 Tg C /year. The central and eastgeography and you  july - august 2013  31

ern Arabian Sea alone contribute an average of ~45 Tg C yr/year to the atmosphere.

Total and new production Ocean biota mainly consists of single-celled micro-organisms called phytoplankton, present in the upper, sunlit layer of the ocean called the euphotic zone. In the presence of sunlight phytoplankton converts inorganic CO2 into organic carbon through photosynthesis (Fig.1).

The amount of carbon thus fixed by phytoplankton through the synthesis of organic carbon, measured as carbon per unit volume of water per unit time, is termed primary production. Once formed, this organic matter faces the immediate possibility of decomposition back to CO2, phosphate, ammonia and other nutrients through consumption by herbivorous zooplankton and degradation by bacteria. Some portion of the primary production is, however, exported to deeper waters through higher trophic levels. A small part (~1 per cent) might also end up in the sediments.

This process by which sinking of organic matter effectively removes CO2 from atmosphere to the deeper ocean is known as the ‘biological pump’.

Availability of sunlight is one of the major limiting factors of primary productivity, as light intensity decreases exponentially with depth. The general limit of light penetration, even in open ocean waters, is approximately 100-150 m. Apart from sunlight, CO2 and H2O, minute quantities of elements such as N, P, Fe, Si etc., are also essential for phytoplankton growth, the absence of which limits photosynthesis and primary production.

Supply of nitrogenous nutrients is considered to be the major limiting factor of oceanic primary production in many regions. Primary production is further partitioned on the basis of the nitrogen source: ‘new’ production supported by nitrate brought into the euphotic zone from the deep, riverine and atmospheric inputs; and, ‘regenerated’ production supported by ammonium and urea, derived from biological processes occurring within the euphotic zone. Ammonium and urea can circulate indefinitely under a quasi-steady state or form an ideal closed system if there is no loss from the phytoplankton population. But there are losses through the sinking of particulate matter, mixing and by predation by zooplankton in the real ocean and therefore other sources of

Region

Period

Nitrate uptake rate (mmol N m-2/day)

f-ratio*

NW and central Arabian Sea

Autumn inter-monsoon

2.7-5.3

0.09-0.14

0.4-5.2 4.3-6.4 1.3-9.8 0.56-6.8 0.63-2.9 1.0-4.3 5.7-23.2 0.63-20.91 1.95-19.70 0.35-1.58 0.17-8.85 0.98-10.67 4.1-88.9 3.1* (n=5) 4.8* (n=5) 0.3-2.5 0.87-7.2 0.34-4.4 0.3-5.1

0.05-0.35 0.05-0.4 0.20-0.41 0.01-0.27 0.14-0.29 0.11-0.53 0.33-0.61 0.17-0.91 0.46-0.87 0.51-0.82 0.11-0.81 0.50-0.87 0.12-0.92 <0.05 <0.05 0.17-0.52 0.03-0.31 0.06-0.24 0.07-0.41

Spring inter-monsoon SW monsoon Autumn inter-monsoon NE monsoon Autumn inter-monsoon NE Arabian Sea NE monsoon Late NE monsoon Late NE monsoon NE monsoon Spring inter-monsoon Bay of Bengal Autumn inter-monsoon Spring inter-monsoon Omani coast Autumn inter-monsoon Spring inter-monsoon SW monsoon Autumn inter-monsoon NE monsoon Autumn inter-monsoon Gulf of Oman Autumn inter-monsoon 32  july - august 2013  geography and you

Table 1: Region, period of sampling, new or export production and f ratios

*the f ratio (the ratio of new to total production that varies from 0 to 1) defines the strength of the biological pump.

0.9-5.8

2.5 3-9

0.8-4.5 0.6

0.9 0.5-4.8

5.5-19.0 (SWM) 0.7-6.0 (NEM) 0.1-3.0 (SIM)

0.4.-8.8

0.6-2.2 18.3-24.2 1.8-12.2

10.0-30.0 0.9-12.5

0.06

4.9-9.2

4.47

Fig 1: new production (mmol n m-2/day) over the world oceans. yellow rectangles show the study area.

nitrogen are needed. The sum of the losses, is balanced by nitrogen fixation or by any other possible sources of non-regenerated nitrogen.

The ratio of new to total production is called the f ratio (varies from 0 to 1), which defines the strength of the biological pump. It represents the probability that a nitrogen atom is assimilated by phytoplankton due to new production. New and regenerated productivity may be directly measured using the 15N tracer technique. Isotopic ratio of even low concentrations of nitrogen can now be measured with sufficiently high precision using an isotope ratio mass spectrometer with improved electronics, vacuum system and ion optics.

15N studies in northern Indian Ocean

New productivity measurements were carried out in the western and central Arabian Sea under U S Joint Global Ocean Flux Study (US JGOFS) programme. Our group too has been carrying out such measurements in the eastern part of the Arabian Sea independently from 2003 onwards.

In addition, we have also completed new production measurements in the Bay of Bengal (Table 1).

A significant seasonal and geographical variation in the new production and f-ratios are observed in the Arabian Sea. A large variation in the N-uptake rate, ranging from 0.1 to 13 mmol N m-2/day has also been reported during the spring inter-monsoon and the summer monsoon for the

northern Arabian Sea. Very high new production has been found in the north-eastern Arabian Sea during winter with a lower f ratio, averaging around 0.19. A general trend of spatial increase in the new production from south to north has been observed. In addition, we have found the presence of two different biogeochemical provinces in eastern Arabian Sea during the late winter monsoon: less productive southern and more productive northern regions.

This may be the effect of more intense winter cooling towards the north. The southern sector is characterised by low column N-uptake and very low f-ratio.

New production during the pre-monsoon in the Bay of Bengal was higher than that in the post-monsoon (Table 1). Overall, new production for the region during the pre-monsoon was almost twice the average value observed during the post-monsoon period. However, the average f ratio estimated for the entire region increased to 0.70 (±0.1) during pre-monsoon as compared to 0.5 during the post-monsoon.

In the end all the measurements in this and other seas cumulatively will tell us how the export of carbon from the atmosphere is changing. The calculation of a precise rate of global warming will ensure remedial actions accordingly.

The author is outstanding scientist, Physical Research Laboratory, Navrangpura, Ahmedabad. rramesh@prl.res.in geography and you  july - august 2013  33

E arth

s c i e n c e t ec h n o l o g i e s

Geospatial Framework for Water Resources

With the ever increasing demands of the society, it is necessary to identify issues and concerns related to water, as well as develop and implement plans with solutions that are environmentally, socially and economically sustainable at various levels. There is seldom proper coordination seen in the water resource projects which is essential for ensuring collective sustainability.

A K Gosain

34 ď&#x201A;§ july - august 2013 ď&#x201A;§ Geography and You

GODAVARI RIVER BASIN

Geography and You  july - august 2013  35

W

ater resource development projects of varied size and scales are inevitable with the ever increasing demands of the society. However, projects inherited—ranging from command areas of millions of hectares to very small local level ones have overlapping and at times conflicting objectives. Thus, there is seldom adequate coordination essential for ensuring collective sustainability. Integrated watershed development and management is the accepted answer but it in turn requires a comprehensive framework that can enable a planning process involving all the stakeholders at different levels and scales. Such a compulsory unified hydrological framework is essential to evaluate the cause and effect of all the proposed actions within the drainage basins.

and tools for analysing, visualising and modelling the data contained within it.

A geographic information system (GIS) portal has been formulated using the ArcHydro data model for the general users to access the hydrological information based on the soil and water assessment tool (SWAT) hydrological modelling (Fig.2). The Arc Hydro data model (Fig.1) enables a watershed to be described in a single geodatabase which can be used by GIS based hydrologic and hydraulic model to simulate watersheds. ArcHydro provides means for linking simulation models through a common data storage system. Thus, a scheme that reflects temporal and geospatial hydrologic data was created to support surface water hydrology and hydrography modelling at any scale.

Integrated water resources framework for India: A comprehensive planning process should cooperatively work towards identifying the water resource concerns, as well as develop and implement plans with solutions that are environmentally, socially and economically sustainable at various connectivity levels of the drainage system. It is important to understand that integrated water resource management should not merely imply the maintenance of an inventory of activities to be undertaken within a hydrological unit. It also requires the collation of information needed to evaluate the cause and effect of all the proposed actions within the drainage basin.

The watershed is the smallest unit where the evaluation of man induced impacts upon natural resources becomes possible. The impact at the watershed level will be experienced at a higher level within the drainage basin, and its assessment will require a regularly maintained and updated framework. The development of a hydrologic information system component is the logical response to meet the specific needs of the various end-users, which consists of a database coupled with tools for acquiring data to fill the database

Data storage, sharing and protection: The GIS data is stored in a geodatabase using ArcSDE and Microsoft SQL server. ArcSDE allows administering spatial data stored in a relational database management system and provides access to data required for client applications. By transferring almost all GIS data into the ArcSDE geodatabase, a centralised resource for geospatial data is created that can be accessed through the intranet and internet by various GIS applications and functionalities designed to serve its many GIS users.

Distributing data and GIS functionality: With the help of built-in functionalities and customised ArcGIS Server applications that use .NET technology and Active Server Pages(ASP), allows enterprise GIS applications to be built that can be centrally managed and accessed via web-based interfaces, custom applications, or traditional desktop GIS. Built on ArcObjects, ArcGIS server can provide all the strength of advanced GIS functionalities in a distributed multiuser setting.

A user can generate custom maps and tables in real time. The data delivery mechanism is streamlined, user friendly, and cost-effective.

Fig 1: Hydro data model Landuse and Soil dataset

Socio-econmic dataset

Drainage dataset Hydrography dataset

36  july - august 2013  Geography and You

Administrative dataset

Raster dataset TS/data Tables

Fig 2: Framework of hydro geodatabase www.gisserver.civil.iitd.ac.in

The watershed is the smallest unit where the evaluation of man induced impacts upon natural resources can be undertaken.

GIS interface for analysis of model results: The web based interface is available at www. gisserver.civil.iitd.ac.in/nat.com. Fig.2 shows the user view of the main page. The user can zoom in further to view the basin, catchment and sub-catchment level. The standardisation of the drainage area was done by giving the unique identification number at different levels, which can be used as reference for users across departments. The user has been given the option of selecting the basin, catchment or sub-catchment

as per his/her interest/requirement. The user is then provided with a large range of outputs generated through the hydrological model SWAT with the different data sets such as those of India Meteorological Department for the period of 1971 to 2005, regional climate model (RCM) data sets pertaining to various scenarios, etc.

The impact of climate change on water resources of the country has also been quantified using several Intergovernmental Panel on Climate Change (IPCC) scenarios.

SWAT model outputs of water balance components, flow, water quality parameters such as nitrite, nitrate, ammonium, organic nitrogen, organic phosphorus, mineral phosphorus, carbonaceous biochemical oxygen demand and dissolved oxygen, are options that are available to the user for analysis. The development of the geospatial web portal was thus to showcase the viability of the solution of addressing the complex water resources issues of the country and is a scientific platform for creating methodologies to evaluate the sustainability of the actions taken by the society as a whole.

The author is professor, Civil Engineering Department, Indian Institute of Technology, Delhi. gosain@civil.iitd.ac.in Geography and You  july - august 2013  37

(MoEF 2013-14/2)

Elements of the framework: The common framework for water resources planning and management requires creation of base layers at different scales so as to cater to the relevant problems at respective scales. However, it is imperative that all these scales should merge through the GIS environment for aggregation and integration to be possible. The major elements of the framework is shown in the Fig 1. ArcHydro data model could only meet the basic information on drainage—the geodatabase was extended to capture the information related to administrative area, landuse, soil feature class and non-spatial data. ArcHydro data model was also extended to support SWAT model output.

E arth science technologies

38  july - august 2013  Geography and You

Swati Basu and E N Rajagopal

Weather Modelling

NATHULA PASS, SIKKIM

A seamless approach across spatial and temporal scales using the earth system modelling framework is the key for providing realistic prediction of weather and climate. Ensemble based forecasting and data assimilation techniques are being used for estimating the uncertainty and providing probabilistic forecasts to end users.

Geography and You ď&#x201A;§ july - august 2013 ď&#x201A;§ 39

W

eather and climate information plays an important role in shaping the country’s economic and strategic activities. India is emerging as a global player in various sectors and it has resulted in the increase in demand for accurate weather and climate prediction for applications in various sectors. Weather forecasting research in data assimilation and, weather and climate modelling (short, medium and seasonal) using computerbased Numerical Weather Prediction (NWP) models is a well-established practice now, which is being spearheaded in India by the National Centre for Medium Range Weather Forecasting (NCMRWF). During the last two decades, the accuracy of weather prediction has improved significantly, with better understanding of the underlying physical and dynamic processes, quality and quantity of meteorological observations; especially from satellites and availability of progressively increasing computing power.

Atmospheric modelling

The concept of a unified modelling system for seamless prediction of weather and climate has gained importance and acceptance in recent times. An unified model (UM) and the associated 4D-VAR (four-dimensional variational) data assimilation system have been successfully implemented at NCMRWF. A regional version of the UM has also been implemented and tested for few synoptic cases. More detailed short-range forecasts are provided by this high-resolution 40  July july - august 2013  Geography and You

regional version which has a more detailed representation of orography and is able to represent certain atmospheric processes more accurately.

Verification of model forecasts

The last eight years' record (2005-2013) of the root-mean-square error (RMSE) against observations from Indian Radiosonde stations of 3-day forecasts shows that the prediction skills have improved between 7 and 8 per cent. This improvement resulted from periodic increase in the resolution of the model and the capability to assimilate satellite radiances.

Atmospheric observations

Atmospheric observations are quite heterogeneous in terms of their horizontal, vertical and temporal resolution. On the other hand NWP models need a regularly spaced and balanced initial condition of the atmosphere to start time integration. Process of converting the information in observations to the initial condition required for NWP models is known as data assimilation (DA). Only observations that qualify stringent quality control checks are accepted by the DA system.

Utilisation of satellite observations

The science of meteorology and the practice of weather forecasting has immensely improved over the years owing to the enhanced ability of the global remote sensing community to observe the 3-D atmosphere. This is significant in view of the limited scope for expansion of conventional data network to meet the input data requirements. As India is surrounded by data sparse oceanic region, there is strong motivation to make optimum use of data from remote sensing observational platforms. The various types of satellite observations/ sensors that are used at NCMRWF are described below.

Atmospheric motion vectors: Geostationary satellites orbit earth in a geosynchronous orbit (~36,000 km above earth) with the orbital period same as the earth’s rotation period. Geostationary satellites give the continuous observation of

Atmospheric observations are quite heterogeneous in terms of their horizontal, vertical and temporal resolution. specific area above the earth. Information about the upper air wind is obtained by tracking the displacement of clouds, water vapour, etc., by an automatic pattern recognition technique. The procedure has also been applied to generate data from polar-orbiting satellites (a sun synchronous orbit ~1000 km above earth). This is popularly known as atmospheric motion vectors and widely used in numerical weather prediction.

Ocean surface scatterometer: Satellite sensors operating at microwave frequencies can make measurements of the ocean surface under nearly all-weather conditions. Scatterometers are radar instruments that measure the radar backscatter from a part of the ocean surface, which depends on wind speed, wind direction, and observation geometry. Oceansat-2, which is an Indian Remote Sensing satellite dedicated to ocean research, has a scatterometer onboard.

Satellite Radiances: Satellites do not measure temperature and moisture directly—they measure radiances (amount of radiation emitted into space from different atmospheric layers) in various wave length bands. Vertical profiles of temperature and moisture can be obtained from radiances sensed by different channels using a mathematical model. However modern day NWP systems can assimilate radiances directly instead of using the temperature and moisture profiles.

Global Positioning System Radio Occultation (GPSRO) from Low Earth Orbit satellites: The GPSRO technique involves a low earth orbit (~2000 km above earth) satellite receiving a signal from a GPS satellite. The signal has to pass through the atmosphere and gets refracted along the way, and the magnitude of refraction depends on the temperature and moisture content in the atmosphere.

Megha-Tropiques: The Indo-French MeghaTropiques satellite’s payload consists of MADRAS (Microwave Analysis and Detection of Rain and Atmospheric Systems—a microwave imager to measure precipitation and cloud properties), SAPHIR (a 6 channel microwave sounding instrument near the absorption band of water vapour at 183 GHz for the retrieval of water vapour vertical profile and horizontal distribution), and ScaRaB (Scanner for Radiation Budget—an optical scanning radiometer devoted to the measurements of radiative fluxes at the top-of-atmosphere in the shortwave and longwave domain).

Global data assimilation system

Data assimilation systems currently used are either in 3D or 4D variational schemes. Observations from all over the globe are assimilated four times a day viz., 00, 06, 12 and 18 UTC. The assimilation scheme utilises all data collected within ±3 hours of the assimilation time and received within a specified cut-off period.

Recent studies have shown that Ensemble Kalman Filter (EnKF) technique has an advantage in defining flow dependent errors and offers more flexible treatment for model errors aiding a 'hybrid data assimilation' which has been adopted by many leading global NWP centres. NCMRWF too plans to shift to hybrid data assimilation soon.

Global ensemble forecast system

Weather forecasts' uncertainty is due to errors in the initial conditions, and model approximations.

Together, they limit the skill of a deterministic forecast system. Ensemble forecasting has emerged as the practical way of estimating the forecast uncertainty and making probabilistic Geography and You  july - august 2013  41

Fig 1: Forecast Vs actual rainfall for 6th August 2013 forecast

36N

Observed/ACTUAL

36N

33N

33N

30N

30N

27N

27N

24N

24N

21N

21N

18N

18N

15N

15N

12N

12N

9N

9N

cm rainfall 64 32 16 8 4 2 1

6N

0.1

6N 65E

70E

75E

80E

85E

90E

95E

100E

1-2 cm probability

36N

65E

70E

75E

80E

33N

30N

30N

27N

27N

24N

24N

21N

21N

18N

18N

15N

15N

12N

12N

9N

9N

90E

95E

100E

2-5 cm probability

36N

33N

85E

percentage of probability 95 65 35 5

6N

6N 65E

70E

75E

80E

85E

90E

95E

100E

65E

70E

GEFS: Tropical Cyclone Predicted Strike Probability over Bay of Bengal

75E

80E

90E

95E

100E

GEFS: Tropical Cyclone Predicted Tracks over Bay of Bengal

(31 OCT 2012)

(31 OCT 2012)

30N

30N

25N

25N

20N

20N

15N

15N

10N

10N

5N

5N

EQ

85E

Observed Track Forecast Mean Track

5S

EQ

Observed Track Forecast Track: 20 members

5S 60E

70E

80E

90E

100E

110E

60E

70E

80E

90E

100E

Fig 2: Predicted strike probability along with observed track and ensemble mean track (left) and observed track and member tracks (right) for the cyclone 'Nilam'.

42 ď&#x201A;§ july - august 2013 ď&#x201A;§ Geography and You

110E

Scatterometers are radar instruments that measure the radar backscatter from a part of the ocean surface. forecasts. A Global Ensemble Forecasting System (GEFS) has been implemented at NCMRWF and is running in real time.

Probabilistic Quantitative Precipitation Forecast (PQPF): Ensemble forecast systems allow for prediction of the rainfall in probabilistic terms. Fig 1. shows an example of the PQPF plots depicting the forecast rainfall distribution alongside the spatial distribution of rainfall probabilities in the 1-2 cm/ day and 2-5 cm/day categories. The top left panel shows the mean rainfall in the forecast valid for 6th August 2013.

Ensemble Based Tropical Cyclone Track Forecasts: Ensemble forecast system can be used for forecasting the tropical cyclone track. This module has been implemented at NCMRWF for the first time and is used for tracking the cyclones in Bay of Bengal, Arabian Sea, Indian Ocean and other oceanic regions as well. Fig 2 shows the tracks and strike probabilities forecast for the cyclone 'Nilam' on October 31, 2012.

Coupled ocean-atmosphere modelling

Monsoon rainfall prediction is crucial for agriculture, food security and economy of India.

Ocean, atmosphere and land-surface all interact and play dominant roles simultaneously in the genesis of the monsoon. Only atmosphere model is incapable of capturing the variability, and coupled ocean-atmosphere models require higher computing resources and relevant observations from ocean, land-surface and atmosphere to be assimilated to the modelling system of the earth.

In the last decade, in developed nations, due to the availability of computer resources and enhanced earth observations, it became possible to carry out the data assimilation and the model runs for coupled system which has shown good potential to capture the monsoon and tropical variability.

These coupled models are also being developed

with an aim to target seamless prediction suite where the same modelling frame work could be used for both weather (short and medium range) and short-term climate (month and season).

Future plans

As a centre of excellence in weather and climate modelling, NCMRWF will focus on model development in a seamless frame work across scales. Land-surface, ocean and cryosphere of the earth system will be dealt with more sophistication including proper initialisation by their respective data assimilation systems.

The global/regional models and data assimilation systems will be continuously improved and customised for weather/climate systems over Afro-Asian region. The chemical components and dust/aerosol aspects are also being taken up to examine their impact in weather/climate systems over the Indian region. Indiaâ&#x20AC;&#x2122;s capability to launch satellites is an added advantage, and NCMRWF will continue to use advanced techniques to assimilate various remote sensed data into its modelling system. With the recent developments in parallel processing in computing, cloud computing and networking, NCMRWF is also gearing up to use massively parallel computers to take up cutting edge high resolution modelling and data assimilation. Development of novel applications of weather/climate prediction for different sectors like agriculture, water resources, flood/drought management, wind energy, energy management, environment, disaster mitigation, etc. are equally important and will be carried out at NCMRWF in collaboration with end users.

The authors are director and scientist G, respectively, at National Centre for Medium Range Weather Forecasting, New Delhi. rajagopal@ncmrwf.gov.in Geography and You ď&#x201A;§ july - august 2013 ď&#x201A;§ 43

E arth

s c i e n c e t ec h n o l o g i e s

Gas hydrates in KrishnaGodavari offshore basin T Ramprasad, A Mazumdar and P Dewangan

44  july - august 2013  Geography and You

A panoramic view of River Godavari

Methane from gas hydrate deposits could be a viable energy alternative.

The investigations in Krishna-Godavari (KG) and Mahanadi offshore basins and Andaman Sea have established the occurrence of gas hydrate in varied forms. However, the KG offshore basin is one of the most promising petroliferous basins.

Geography and You ď&#x201A;§ july - august 2013 ď&#x201A;§ 45

G

as hydrates are ice-like substances that store huge quantities of methane—1 cubic meter of solid hydrate approximately contains 164 cubic meters of methane and 0.8 cubic meters of pure water. Gas hydrates occur in massive quantities in the KG offshore basin within the fractures or fissures in the sediments below the sea floor. The amount of global carbon trapped in the sediments of the oceanic regions or in the permafrost regions in the form of methane hydrates is twice that are found in the fossil fuels. The biological debris/remnants of the dead animals and plants from land areas transported by the river system, as well as the dead flora/fauna in oceanic areas get buried deep under few kilometres of thick ocean sediments and is degraded by the bacterial activity for eons under very high temperatures.

The methane molecules thus generated find their way into the overlying sediments through the fractures or fissures or sediment pore spaces and gets trapped within the lattice cavities of water molecules and form ice-like structures under low temperature and high pressure conditions. Most of the salts that exist in sea water in sediment pore spaces get expelled during the process of hydrate formation. A gas hydrate stability zone exists in which the gas hydrates are stable between the sea floor and a few hundred meters below. The gas hydrates, world over, are explored using the seismic or acoustic techniques—by the identification of an anomalous seismic reflection called ‘bottom simulating reflection’ (BSR), caused due to a large difference in the acoustic wave velocity between the sediment filled hydrate and the surrounding sediments filled by water/free gas.

Any fluctuations in the temperature and pressure conditions cause dissociation of hydrates and the methane is released which migrates towards the sea floor. As the methane ascends from deep into the shallow sediment layers, it undergoes numerous biological and chemical alterations.

Within the shallow sediment column, the methane concentration increases with depth and the sulphate concentration reduces, where they reach their lowest concentrations known as sulphatemethane interface (SMI). Our studies include the detailed account of various types of these SMI variation curves using them as proxies along with several other geochemical parameters for inferring the numerous geo-biological processes 46  july - august 2013  Geography and You

associated with the formation and dissociation of gas hydrates. The KG offshore basin experiences frequent neo-tectonic activity due to fluid/ gas movement below the fine grained clay/shale sediments causing fractures and faults. Methane moves up these fractures in the KG offshore basin, making way into the gas hydrate stability zone.

In order to harvest these massive hydrates within the vertical fissures, a viable technology is required. World over, gas hydrate exploration is focused on the discovery of gas hydrate deposits in sand formations, which could be exploited using the available gas production technology­— through controlled dissociation of hydrates by a combination of depressurization and thermal heating. Molecular replacement of methane by carbon dioxide is a second technique that scientists are currently working on and may be used to produce gas from the massive hydrates in KG offshore basin in future.

New finds in the KG offshore basin

Drilling/coring activities have confirmed gas hydrate in the continental slope of KG basin, Bay of Bengal and recovered fracture filled gas hydrate.

The geophysical methods like multibeam swath bathymetry helps in understanding the bathymetry of basin, whereas, the high resolution multi-channel seismic (MCS), high resolution seismic (HRS) and sub-bottom profiler data gives detail vertical profile of sediment package. The paleomagnetic measurements reveal the digenesis of magnetic minerals in a gas hydrates with a zone of reduced magnetic susceptibility where most of the magnetic minerals are dissolved. The geophysical and geological exploration lines/ sampling locations in Krishna-Godavari (KG) are shown in Fig 1.

Bathymetric mounds in the offshore basin are formed due to prevalent shale tectonism and are often associated with fluid/gas migration features such as acoustic chimneys, acoustic voids and acoustic turbid layer. Detailed analysis of MCS data in the vicinity of Site NGHP-01-10 suggest large-scale fault system (>5 km) predominantly oriented in NNW-SSE direction near NGHP-0110 site which plays an important role in gas hydrate formation, distribution and thermal regime in the KG basin. The P-wave velocity obtained using unified imaging technique show patchy distribution of hydrates and appropriately predicted the hydrate saturation at Sites NGHP-01-10 to NGHP-01-13.

81o30'E

82o00'E

82o30'E

16o00'N

Fig 1: Map showing bathymetry of Krishna-Godavari (KG) Basin.

Sediment core locations of JOIDES Resolution (prefixed

by J) and Marion Dufresne (prefixed

by M) are shown.

15o30'N 81o30'E

The hydrates maintain continuity along the strike direction of regional faults and show heterogeneous deposit across the fault. The bathymetry data show slumping and sliding features in the midslope region in the form of mass transport deposits in KG offshore basin. The pore water sulphate concentration profiles in KG basin show occurrence of transient (sigmoidal and kink types) and steady state (quasi-linear) sulphate concentration profiles which are attributed partly to the anaerobic oxidation of methane and organo-clastic sulphate reduction. The geophysical data show the acoustic signatures of upward fluid migration from shallow sub-surface, whereas, coring during NGHP expedition-01 confirms the presence of sub-surface gas hydrate deposits in KG basin which can be linked to deep methane sources. The geochemical analysis suggests that shallow methane source can be attributed to high burial flux of organic matter due to high sedimentation rate. The short lived ‘kink’ in the sulphate profiles is interpreted as a result of recent enhancement in vertical methane flux possibly driven by reactivation of fault-fractures systems which provide the conduits for fluid flow.

Microbially mediated anaerobic oxidation of methane (AOM) coupled with sulphate consump-

16o00'N

15o30'N 82o00'E

82o30'E

tion within the sulphate methane transition zone (SMTZ) in marine sediments is a widely recorded biogeochemical reaction and has profound influence on the atmospheric CH4 budget, marine carbon cycle and composition of sediment pore fluids.

End Note

The bathymetric mounds formed due to passive/ shale tectonism are the prominent locations for the formation and accumulation of gas hydrates in the KG offshore basin. Large-scale fault system acts as a conduit for fluid/gas migration and plays an important role in gas hydrate formation and its distribution. The amplitude variation with angle pattern of BSRs also suggests the presence of fracture-filled gas hydrate deposits here. The bathymetry data reveal several slope failures in KG offshore basin which may be related to fluid/gas migration within the gas hydrate stability zone.

The authors are chief scientist, senior scientist, and scientist C, respectively, at CSIR- National Institute of Oceanography, Goa. NIO contribution No. 5428. rprasad@nio.org Geography and You  july - august 2013  47

E arth science technologies

PERI-URBAN AREA OF KOLKATA

T

imely air quality information, even 24 hours in advance can assist those coping with health problems that are aggravated by ground-level ozone, sulphur dioxide, nitrogen dioxide, carbon monoxide, particulate matter and other pollutants.

Air quality advisories or alerts issued when predetermined pollutant threshold exceeds should result in actions to reduce pollution levels and encourage people to avoid polluted areas thereby alleviating adverse effects on health. Briefly, in response to the air quality advisories people can try to take actions against the increased pollution themselves like use public transportation and pool together, stagger work hours or even stay indoors 48 ď&#x201A;§ july - august 2013 ď&#x201A;§ Geography and You

and industry and regulatory agencies may decide on temporary shutdown of polluting factories, thermal power plants, etc. Similarly the traffic controlling authorities can reroute the flow of traffic to avoid hot spot areas.

Apart from these air pollutants resulting from human activities, there are other parameters which affect human health and harm the environment as well. For example, the pollen season that is reasonably well-known to people who are allergic.

The presence of pollen, its density and trajectory, as well as the possibility of being removed from the atmosphere by brief showers, all depend on the weather advisories. Also, the amount of UV

Predicting

Poor

Air Quality Events

Gufran Beig and Neha Parkhi

radiation which not only leads to increase in skin diseases and eye cataracts in humans but also affect plants, aquatic organisms and other natural systems depend on the weather conditions. These radiations also play an important role in modulating the level of air pollutants.

The ‘System of Air Quality and Weather Forecasting and Research’ known as SAFAR system, first of this kind in the country, is successfully developed with indigenous capabilities in record time for National Capital Region of Delhi and dedicated to citizens as an operational system during Commonwealth Games (CWG) 2010.

The early warning system for air quality and

Air pollution is a growing problem in India.

Factories, power plants, automobiles and dust, smoke from bush fires and volcanic eruptions are responsible for pollution.

The deterioration of air quality thus results into a corresponding increase in health problems, eventually inducing the monitoring of air quality and its prediction as a prime necessity in day-to-day life. weather developed under the project proved as a useful machinery to reduce the first hand impact of deteriorated air quality on human health during CWG-2010. The successful implementation of SAFAR in both operational and research mode is recognised by the global scientific communities and Global Atmospheric Watch (GAW). Global Urban Research Meteorology and Environment (GURME) project of United Nation’s World Meteorological Organization appreciated it and also recommended its replication in other metropolises, which is likely to set an example for developing countries. Recently on 1st May 2013, the SAFAR system was dedicated to citizens of Pune MetroGeography and You  july - august 2013  49

Fig 1: A view of Air Quality Monitoring Station (AQMS) and Automatic Weather Station (AWS) at Pune.

politan Region, named ‘SAFAR-Pune’ with more advanced features and value added products.

Under the scheme “Metropolitan Advisories for Cities for Sports, Tourism (Metropolitan Air Quality and Weather Services), Ministry of Earth Sciences (MoES), Govt. of India, has introduced SAFAR for greater metropolitan cities of India to provide location specific air quality information and forecast for the first time in India. The SAFAR system is developed by Indian Institute of Tropical Meteorology (IITM), Pune, along with Earth System Science Organisation (ESSO) partner institutions namely India Meteorological Department (IMD) and National Centre for Medium Range Weather Forecasting (NCMRWF).

System components Observational network: Under the project dense observational network of air quality monitoring stations (AQMS) and automatic weather stations (AWS) (Fig 1) has been established (50 x 50 km domain of metropolitan region) by selecting representative sites of different micro-environments including industrial, residential, background/ cleaner, urban complex, agricultural zones etc.

Air quality indicators monitored at about 3 m from the ground includes particulate matter (PM10, PM2.5), black carbon (BC), ozone (O3), carbon monoxide (CO), carbon dioxide (CO2), oxides of nitrogen (NO, NO2, NOx), volatile or50  july - august 2013  Geography and You

ganic compounds (VOC’s) and mercury (Hg). In addition to this temperature, rainfall, humidity, wind speed, wind direction, and solar radiation are monitored along with ultraviolet radiation flux in terms of erythemal UV dose using AWS and UV-E radiometer. Calibrations of the online analysers are performed at appropriate time intervals using in-built calibrators for some pollutants or with external calibration cylinders with multipoint calibration techniques for other elements.

Development of Emission Inventory: Emission of various air pollutants as a consequence of burning of fossil fuel and bio-fuel in our day to day life for industrial activity, transportation, cooking, power generation, agricultural production, waste disposal and so on is important phenomenon which alters the normal composition of air. In any urban settlement these are the most potential air pollution sources but their contribution and intensity varies with geographical and socio-economical factors. To identify the major air pollution sources in the region and their region specific spatial distribution, scientific approach has to be adopted. Emissions inventory is the most effective scientific tool and most critical input to the 3-D atmospheric chemistry transport models along with meteorological input to forecast the air quality; the quality of forecast depending on the accuracy of emission inventories. It thus helps to implement effective air quality management programme and formulate environmental policy.

Under the project SAFAR a high resolution (1 x 1 km) emission inventory has been developed by ESSO-IITM for NCR-Delhi and for PMR-Pune by using bottom-up approach. Development of emission inventory is a complex process and require huge amount of activity data and knowledge of fundamental scientific processes. The accuracy and reliability of emission inventory has been maintained by collecting unique region specific activity data during the extensive field survey for several months involving more than 200 students of various educational organisations and proper country specific emission factors has been selected to estimate the total emissions from transport, industries, residential and slum sector. The particulate emissions from untouched source, paved and unpaved roads, are also estimated. The spatial distribution of pollutants has been studied by using GIS based statistical model.

Development of Air Quality and Weather Forecasting Model: The air quality forecasting is a highly specialised area and requires huge computational power.

Atmospheric chemistry transport model is used for air quality forecasting. To forecast the air quality of various pollutants along with weather parameters, IITM uses four nested domain starting from near global to the local city level. The inner domain has a resolution of 1.67 x 1.67 km. All these 4 domains run interactively and feedback of meteorology to chemistry and vice-versa has been accounted.

This model requires several key inputs for accurate forecasting. Major among them are—emission inventory of pollutants from various sources, weather parameters, topographical data, land use/ cover data, initial and lateral boundary conditions, etc. The initial and lateral boundary conditions for the outermost domain in meteorological model has been taken either from NCEP reanalysis or from internally generated CFS of NCMRWF whereas for the chemical forecast model, it has been taken from Monitoring Atmospheric Composition and Climate (MACC), a project under MoU between IITM and EU project partners.

DATA TO INFORMATION Under the project, measurements of air quality indicators and weather parameters have been made round the clock and the data is recorded and stored at every five minutes interval for quality checks and scientific analysis. This near real time online raw data is then converted in the public friendly format like Air Quality Index (AQI) or UV-Index

Fig 2: Air Quality Index 400500

301400

Critical

Very Poor

201300 Poor AQI

101200

0-100

Moderate

Good

Health Advisories Health warnings in emergency conditions

Unhealthy for sensitive groups. Members of sensitive groups may experience health effects.

Children and adults who are active outdoors and people with respiratory disease are at greater risk.

Everyone may begin to experience some level of discomfort.

Air quality acceptable for general public; however, for some pollutants there may be a moderate health concern for a very small number of people. Unusually sensitive people should consider limiting prolonged outdoor stays.

Air quality good. Satisfactory and acceptable for general public.

Air pollution poses little or no risk. No cautionary actions are prescribed to the general public.

Proportion of population affected

Severity of effects

Triggers health alert; everyone may experience serious health effects

at SAFAR-control room after quality control and check by an expert scientific team. AQI is a rating used for reporting the quality of air we breathe and the associated health effects (Fig 2). The UV Index is a measure of the amount of skin damaging UV radiation expected to reach the earth’s surface at the time when the sun is highest in the sky (around midday).

SYSTEM PRODUCTS The SAFAR system provides information on current and 1-2 days advance forecast for air quality and weather, harmful radiation and emission scenario over the city area in a very simple and user friendly format. The systems location-specific products include air quality-now, air qualitytomorrow, weather-now, weather-tomorrow, UV Index –skin advisory, AQI-health advisory and city pollution maps. To disseminate the information to maximum stakeholders user friendly platforms have been developed where one can access our products easily including dynamic professional web portal (safar.tropmet.res.in/pune), digital display board system, integrated voice response service (toll free no +91 1800 1801 717), etc. The information is updated at each hour and public may subscribe to the alert network through the website to receive direct e-mail or SMS alerts for extreme weather conditions or air pollution events. All these facilities are available in English, Hindi and regional languages.

DATA COLLECTION AND PROCESSING: The near real time online raw data measured at various AQMS and AWS is transferred to AQMS server located in SAFAR Control Room at IITM, Pune, through the GPRS network. The raw data is then converted to AQI or UV-Index, etc. File transfer processor (FTP) master control server receives current data each hour from AQMS server through wired connectivity whereas the air quality and weather forecasting data for the next day is received from the high performance computation facility of IITM and IMD. The FTP master control server has the responsibility to channelise the data to the web server of SAFAR-Pune and IVRS from where it is fed into the communication network.

The authors are chief project scientist, SAFAR; and programme officer, ENVIS, Indian Institute of Tropical Meteorology, Pune, MoES, New Delhi, respectively. beig@tropmet.res.in Geography and You  july - august 2013  51

E arth

s c i e n c e t ec h n o l o g i e s

M V Sunanda, T Srinivasa Kumar, Dipankar Saikia, S S C Shenoi, Shailesh Nayak

Rewiring the Tsunami Early Warning System

T

he Indian Tsunami Early Warning System (ITEWS) can successfully issue timely and accurate warnings.

However, the 2011 earthquake in Japan and 2012 in Northern Sumatra once again emphasised the limitations in traditional approaches that necessitate improvements.

Thus the Earth System Science Organisation (ESSO) has initiated improvements in the ITEWS that includes establishment of co-located broadband, GPS and strong motion sensors for measuring displacements and ground accelerations in real-time.

The Indian mainland and islands are located in a zone of significant seismic activity, where many earthquakes and accompanying tsunamis have been observed and recorded. The two subduction zones, the Andaman-Nicobar-Sumatra island arc and the Makran region have been identified as tsunamigenic zones in the Indian Ocean based on historical records.

A great shallow foci earthquake of magnitude Mw 9.2 occurred on 26 December 2004 on Andaman-Sumatra subduction zone and generated a massive tsunami that caused extensive destruction all along the Indian mainland and Andaman & Nicobar Islands. In response ESSO successfully set up a tsunami warning centre for Indian Ocean at Indian National Centre for Ocean 52 ď&#x201A;§ july - august 2013 ď&#x201A;§ Geography and You

The Japan Meteorological Agency (JMA) on 11 March 2011 warned that a 3-m-plus tsunami would hit northeastern Japan. In fact, the wave that came ashore stood more than 10 m high — reaching 40 m in some places.

Geography and You  july - august 2013  53

Information Services (INCOIS), Hyderabad. Since its inception in October 2007 till June 2013, the Indian Tsunami Early Warning Centre (ITEWC) successfully monitored 356 earthquakes of M > 6.5, out of which 60 were in the Indian Ocean region (both on land and under-sea). For all these major events in the Indian Ocean, timely advisories were generated based on estimated time of wave arrivals and wave heights and the stakeholders were informed through bulletins. This avoided false alarms and unnecessary evacuation from the coastal areas.

One of the most critical aspects of tsunami warning system is the quick estimation of earthquake parameters with reasonable accuracy in the shortest possible time. The consequences of diametrically opposite behaviours of large earthquakes, in terms of tsunamis, in the recent times—Tohoku-oki (2011) in the Pacific and Northern Sumatra (2012) in the Indian Ocean, demand the improvement in tsunami early warning systems.

Limitations of the current warning procedures

Traditionally, the estimation of tsunamigenic potential of an earthquake relies on the measurement of the magnitude of the earthquake, which is not reliable to the extent that it should be. For example, the Tohoku-oki earthquake of magnitude Mw 9.0 was initially underestimated by the Japan Meteorological Agency (JMA), which inarguably is one of the finest centres for earthquake and tsunami early warnings. The earthquake detection centres elsewhere too estimated much lower magnitudes (Mw 7.9 – 8.0) initially. The magnitude of the earthquake was underestimated at least by an order one to two (M 7.2 after 8.6 seconds and revised to M 8.1 after 116.8 sec) [M. Hoshiba, et al., 2011, ‘Outline of the 2011 off the Pacific coast of Tohoku earthquake - Earthquake early warning and observed seismic intensity’, Earth Planets and Space], which in turn underestimated the expected tsunami wave height as 3–6 m. But in reality, the sudden sea-floor displacement generated a massive tsunami that overtopped the tsunami protection walls and broke through as far as 10 km inland along the coast.

Though JMA could issue the warnings within 3 minutes, unfortunately, that was based on the gross underestimation of the earthquake magnitude (8.6 M instead of 9 M). The accurate estimate of size of the earthquake could have resulted in an accurate estimate of tsunami wave height. The actual wave height reported from the adjacent areas of Tohoku 54  july - august 2013  Geography and You

was 39.7 m (at Miyako).

On the other hand, in the case of Northern Sumatra earthquake of magnitude Mw 8.5 on 11 April 2012 only a small ocean-wide tsunami (~30 cm at Sabang, Indonesia) was generated in contrast to the estimated wave heights of 6-8 m initially. Later when more data became available, it was realised that it was a strike-slip earthquake which generated very little or no vertical motion in the ocean floor hence avoiding the sudden disturbance of water column essential for the generation of a tsunami.

Similar was the case with the 2005 Nias earthquake (8.6 M), Indonesia. That event too did not generate a sizable tsunami as expected [A O Konca, et al., 2007 ‘Rupture Kinematics of the 2005 Mw 8.6 Nias–Simeulue Earthquake from the Joint Inversion of Seismic and Geodetic Data’, Bulletin of the Seismological Society of America].

To overcome such difficulties and to understand the fault geometry that governs tsunamis, it is essential to estimate the seismic moment tensor solutions. However, the estimate requires a larger amount of data that becomes available only after a certain amount of time. Longer wait for sufficient data to make a decision at the warning centre is unfeasible as the warning centre is expected to provide warnings at the earliest. Often the procedure to predict tsunami wave height and travel time depends on the worst cases and there might be overestimates in those that deviate from such scenarios, especially the strike-slip ones.

New Approaches

As illustrated above, traditional methods of earthquake magnitude estimation only based on seismic data and the prediction of tsunami wave heights can go wrong if the earthquake mechanism is not taken in account in addition to its magnitude.

This is more serious for near source regions like Andaman and Sumatra coast as they lie very close to the subduction zone and the available time for warnings and response is too short. This was precisely the limitation faced during the 2011 Tohoku earthquake and the 2012 Northern Sumatra earthquake that necessitated the development of new tools and techniques for determining the true size of an undersea earthquake and the actual ground displacement. Such techniques call for receiving and analysing data from multiple sensors like seismometers, GPS sensors, strong motion sensors, etc. in real-time.

Use of GPS technology: Monitoring the crustal

deformation in real-time makes it feasible to achieve rapid estimation of actual earthquake scales, since the measured permanent displacement directly gives us the true size of the earthquake by seismic moment, which in turn, can be used for tsunami warning. The real-time deformation monitoring technique is based on near-field global position system (GPS). Using coastal GPS stations’ data near the epicentre, the new method estimates the energy transferred by undersea earthquake to the ocean to generate a tsunami [S V Sobolev, et al., 2006, ‘Towards Real-time Tsunami Amplitude Prediction’, Eos Transactions, American Geophysical Union]. Recent analysis showed that by using GPS displacements, it is possible to calculate how far the stations moved because of the quake and that in turn helped in deriving an earthquake’s true size, called moment magnitude. This magnitude is directly related to earthquake’s potential for generating tsunamis[S K Singh, et al., 2012, ‘A Method for Rapid Estimation of Moment Magnitude for Early Tsunami Warning Based on Coastal GPS Networks’, Seismological Research Letters]. This method allows the rapid estimation of seismic moment tensor solutions and the earthquake source determination in a shortest possible time compared to the traditional approaches.

Using Strong Motion Sensors: During large earthquakes the broadband seismometers at the near source region often get clipped due to saturation. To overcome this the stations are generally augmented with strong motion accelerometer. The near source dense network of strong motion sensors provides unsaturated recordings of moderate to large earthquakes and early peak amplitudes from these records can be used to estimate the magnitude of an earthquake [A Zollo, et al., 2006, ‘Earthquake magnitude estimation from peak amplitudes of very early seismic signals on strong motion records’, Geophysical Research Letters]. When even few seconds are critical for a local tsunami warning, the quick estimation of earthquake magnitude, source parameters using accelerometers, broadband seismometers and GPS receivers could result in improved tsunami early warning system.

Rapid estimation of fault parameters using W-phase: After the occurrence of an earthquake it is very important to determine the fault geometry to estimate its tsunamigenic potential. However, it is difficult to calculate these parameters at an initial stage as we need surface wave data over longer period for accurate estimation. To compute and

interpret the kinematics of deformation using moment tensor the W-phase is used, since it carries long period information of the source at a much faster speed than the traditional surface waves [H Kanamori, 2008, ‘Source inversion of W-phase: speeding up seismic tsunami warning’, Geophysical Journal International]. Hence the W-phase inversion method can be used for rapid and robust determination of seismic source parameters with sufficient accuracy for tsunami warning.

Conclusion

In order to provide accurate and rapid tsunami warnings, the most critical part lies in estimating the earthquake magnitude and source parameters accurately and as fast as possible. The advantage of such joint network of broadband seismometers, accelerometers and GPS receivers is that it will provide a continuous update on accurate source parameters with higher accuracies.

The ESSO-INCOIS has recently implemented a nation-wide project to connect all standalone remote seismic as well as GPS stations established under various projects all over the country through VSAT to fetch real-time data. A parallel data centre has been made operational at India Meteorological Department, New Delhi along with the ESSOINCOIS to acquire, process and utilise the dataset and made operational. The data received from broadband seismometers, accelerometers and GPS receivers is being processed in real-time using VRS3Net and SeisComP software by which improved earthquake parameters and displacements are being calculated. The users can also download this data from the website for research. In addition, ESSO-INCOIS has taken up a project on establishing an integrated network of 35 GPS receivers and strong motion accelerometers at seismically active Andaman and Nicobar Islands.

The data from these stations will also be acquired and processed through well established data centre for enhancing the timeliness and accuracies of tsunami early warnings. The site selection is underway for installation of the sensors and by end of December, 2013 the Andaman and Nicobar GPS and strong motion network would be made operational.

The authors are scientist C, scientist F, scientist B and director, respectively, at Indian National Centre for Ocean Information Services, Hyderabad and secretary, Ministry of Earth Sciences. srinivas@incois.gov.in Geography and You  july - august 2013  55

E arth

s c i e n c e t ec h n o l o g i e s

Ecosystem Services from Marine Living Resources V N Sanjeevan and Asha Devi CR

56 ď&#x201A;§ july - august 2013 ď&#x201A;§ Geography and You

The role of marine organisms as providers of ecosystem services in the South-East and North-East Arabian Sea upwelling systems is elucidated in this essay. Services such as primary production, fish production, carbon sequestration, algal blooms and ecotourism are thus studied.

Geography and You ď&#x201A;§ july - august 2013 ď&#x201A;§ 57

O

ceans cover 71 per cent of the earth’s surface and supports a variety of life ranging from viruses, bacteria, fungi, moulds, microscopic plants (phytoplankton), rooted plants (sea grass, kelps etc), micro animals that drift (zooplankton) to fishes, reptiles, birds and mammals such as dolphins and whales. Irrespective of their size, abundance or the ecological niche they occupy, these groups form key elements of ecosystem services and therefore are considered ‘resources’ by mankind.

The Millennium Ecosystem Assessment of United Nations (2005) defines ecosystem services as the benefits people obtain from ecosystems and classify these services as (i) supporting services— those that are necessary for the production of all other ecosystem services (e.g. primary production), (ii) provisioning services—products obtained from ecosystems (e.g. fish catch, drugs etc), (iii) regulating services—benefits obtained from the regulation of ecosystem processes (carbon sequestration, climate change, algal blooms etc.) and (iv) cultural services—non material services (eg. scientific discoveries, ecotourism etc.). The modern expansion of ecosystem services concept include socio-economic and conservation objectives.

Marine Living Resources (MLR) Programme, implemented by the Centre for Marine Living Resources and Ecology (CMLRE), Ministry of Earth Sciences, is designed to understand and adopt ecosystem based approaches to better the management of MLR. This article presents the current status and future challenges in the sustenance of ecosystem services from two small scale regional units (SSRUs), the South East Arabian Sea (SEAS) and the North East Arabian Sea (NEAS), that form the eastern boundary of Arabian Sea large marine ecosystem (LME).

Ecosystem Support Services Primary production (PP) essentially is the fixation of atmospheric CO2 to organic carbon by chlorophyll containing phytoplankton through the process of photosynthesis.

Though eukaryotic phytoplankton are the principal autotrophs in the marine ecosystem, an increasing body of evidence suggests a dominant role played by prokaryotic autotrophs in supporting the PP of oligotrophic and upwelled waters. A clear understanding of the physico-chemical drivers that supply nutrients to the euphotic zone (upper sunlit zone) and information on the biological interac58  july - august 2013  Geography and You

tions involving phytoplankton-zooplankton size are mandatory to develop models that can explain energy transfer through trophic levels and estimate fishery yields from an ecosystem.

The SSRU’s, SEAS and NEAS (Fig 1) falling within the Arabian Sea LME are characterised by distinct physical, chemical and biological processes corresponding with the summer monsoon (SM: June -September), fall inter monsoon (FIM :October), winter monsoon (WM:November-February) and spring inter monsoon (SIM:March-May) seasons.

During SM, Arabian Sea LME is under the grip of strong south westerlies, forcing intense upwelling and offshore transport along the coast of Somalia and Oman and moderate upwelling along SEAS. The Arabian Sea Paradox however shows that zones of intense upwelling and nutrient availability do not necessarily support high PP but SEAS with moderate upwelling supports relatively higher PP. S W A Naqvi, et al., 2010 in their work titled, ‘The Arabian Sea as a high-nutrient, low-chlorophyll region during the late southwest monsoon’, published in Biogeosciences, have attributed the high nutrient, low PP of western and central Arabian Sea to iron limitations and the moderately high PP in the SEAS to adequate iron supply and to the long residence time of upwelled waters over a relatively wide shelf.

Like most of the coastal upwelling systems world over, the SEAS upwelling system is dominated by small coastal pelagic fishes represented by oil sardine (Sardinella longiceps), Indian mackerel (Rastrelliger kanangurta) and anchovies (Stolephorus sp.), which contribute to as much as 50 per cent of the estimated maximum sustainable fishery yield (MSY) from the SEAS–SSRU (1.70 MT). Sanjeevan et al., 2011 in their study, ‘Revalidation of Potential Yield from Indian EEZ - A Trophodynamic Approach’ worked out 1.36 MT for SEAS and 1.07 MT of fish resource for NEAS by applying transfer efficiencies for PP ranging from 7.21 to 18.16 for seasons in coastal and oceanic waters. Fishery yield estimated through this approach (4.32 MT) was close to the estimates from catch-effort data (4.41 MT), thereby proving the usefulness of satellite derived data in the estimate of tertiary production and fish yield.

Ecosystem Provisioning Services The 2007-2012 average annual fish yield (AAY) from Indian EEZ (~3.1 MT) is almost 70 per cent of the estimated

24 22 20 18

india NEAS

Latitude (oN)

16 14 12 10 8

SEAS

6 4

Map not to scale

64 70 66 68 76 74 72 NEAS: north east Arabian Sea Longitude (oE) SEAS: south east Arabian Sea

80 82 78 Diurnal stations Routine stations

Fig 1: Eastern Arabian Sea Stations

MSY (4.41 MT),the share of SEAS and NEAS to the total MSY being 1.70 and 1.25 MT respectively.

Using trophic models Pauly and Christenson in 1995 published studies titled ‘Primary production required to sustain global fisheries’ in Nature, estimating the PP requirements (PPR) to sustain fisheries in the open ocean, upwelling systems and tropical shelves to be 1.8, 25.1 and 24.0 respectively against the global ocean average of 8 PPR. They noted that in the coastal upwelling systems and tropical shelves, fishing had already moved down the food web, where intense overfishing is causing significant loss of spawning biomass and biodiversity, and massive changes in the community structure, including large fish being replaced by short-lived fishes (small pelagic fishes, cephalopods, jelly fish etc). Studies conducted in the Indian EEZ under the MLR Programme and the reports from other fishery agencies in India are in agreement with the above observations. These studies indicate a sharp decline in the catches of large fishes and increase in the catches of small pelagic fishes such as sardine, mackerel and anchovies. Thus ‘fishing down the food-web’ (ibid.) is true in the Indian context also.

As the scope for further enhancing yield from the coastal fishing grounds are dull, there is a need to search for alternate sources to meet the increasing human demand for fish. New and exploitable

Fig 2: Micro algal blooms depicted as green scum in the Arabian Sea are harmful to the ecosystem and at times to humans too.

Geography and You  july - august 2013  59

resources in the Arabian Sea include myctophid fishery, deep sea fishery and oceanic squids. The deep-sea and distant water fishery surveys initiated under the MLR is designed specifically to meet these challenges.

Myctophid Fishery: Myctophids or lantern fishes are a group of mesopelagic fishes occurring abundantly in Central, Western and Northern Arabian Sea and also in moderate abundance in the Indian EEZ. MLR surveys during 2007-12 have quantified the resource availability of myctophids in the Indian EEZ to be around 1 million tonne dominated by species such as Diaphus watasei, Myctophum spinosum, and Benthosema fibulatum (Fig 3).

Gjosaetes et al., 1980 in their study, ‘A review of the world resources of mesopelagic fish’, published in FAO Technical Report, estimated the potential for myctophid fishery in world oceans to be around 600 million tonnes with its largest concentration in the northern Arabian Sea along the Gulf of Aden, Gulf of Oman and the Coast of Pakistan. The US GLOBEC acoustic 1993 survey estimated a potential of 100 million tonnes of myctophids in the Arabian Sea dominated by Benthosema pterotum.

As these fishes have a short life span of less than one year it is expected that the biomass is regenerated on an annual basis, giving scope for its commercial exploitation without disturbing the trophic links.

Even a 10 per cent harvest can yield ~10 million tonne of fish, which is thrice India’s AAY from the marine sector.

Myctophid meat contain high wax and lipid and is therefore is not suitable for direct human consumption. Technological challenges on harvesting, post harvesting and product development need to be overcome, before venturing into commercial scale myctophid fishing. Preliminary results of MLR indicates that myctophid oil is rich in poly unsaturated fatty acids (PUFA) especially the Omega-3 with high levels of Docosahexaenoic acid (DHA) and Eicosapentaenoic acid (EPA) that are comparable to fish oils from oil-sardines. Therefore, there is a good potential to use myctophid fish meal as food for livestock, poultry and aquatics.

Deep-sea Fishery: The deep-sea trawl survey’s in the Indian EEZ under the MLR scheme have provided information on the qualitative nature of the fishery in the depth zones 200 to 1000 meters. These studies indicate a potential for harvesting certain groups such as the green-eye (Chlorophthalmus sp.), blackruffs and deep-sea shrimps from the south-west 60  july - august 2013  Geography and You

and south-east coasts. However, the slow growth rates and the vulnerability of these stocks to commercial fishing, demands a thorough investigation on the growth parameters, before deep-sea fishing advisories are provided to commercial fishermen.

The oceanic squid, Sthenoteuthis oualaniensis found in the deeper-waters (200-300 m) of continental slopes is estimated to have a potential of 3 to 4 million tonnes (Zuyeve et al., 2002) of which one to 1.5 million tonnes are found in the Central Arabian Sea. Taking into consideration, the high abundance, large size, short life span, fast growth and near monopoly of this species in the higher trophic niche S. oualaniensis was termed as the ‘Masters of the Arabian Sea’ [ M V Chesalin et al., 1995, ‘Squid Sthenoteuthisoualaniensis (Cephalopoda: Ommastrephidae) is the ‘master’ of the Arabian Sea’, 12th International Malacological Congress].

Ecosystem Regulating Services Phytoplankton besides being food providers to the marine ecosystem, play a crucial role in the removal of atmospheric CO2 and its sequestration down the food web. Aquatic systems contribute to as much as 41 per cent of the global PP. Despite light limitations on aquatic PP, their higher turn-over rates, small size and fast growth makes them efficient tools to combat increased atmospheric CO2 levels.

However, areas such as the northern Arabian Sea having extensive oxygen minimum zones in the intermediate depths can at times become a source of CO2, nitrous oxide and methane all of which are known green house gases. V V S S Sarma et al., 1996 in their study ‘Seasonal variations in inorganic carbon components in the central and eastern Arabian Sea’, published in Current Science, reported the Central and Eastern Arabian Sea as perennial sources of atmospheric CO2 and noted that the flux of CO2 to atmosphere was maximum around 16°N of Central Arabian Sea during the monsoon season.

S W A Naqvi et al., 2006 in their study, ‘Coastal versus open-ocean denitrification in the Arabian Sea’, published in Biogeosciences, observed that nitrous oxide production occur in the denitrification zones of perennial open ocean systems and seasonal coastal systems of Arabian Sea and that the process has intensified in the coastal systems over the past few decades presumably due to enhanced nutrient loading from land. Climate variability and global warming are expected to accelerate in the coming decades and therefore the role of aquatic ecosystems

Diaphus watasei

Benthosema pterotum

Benthosema fibulatum

Myctophum spinosum Fig 3: Lantern fishes of Arabian Sea

as source of green house gases needs to be investigated in detail. Definitely, there is an urgent need to quantify emissions from the Arabian sea and include them in the regional carbon budgets, in which India should take the lead role.

Harmful Algal Blooms: Micro algal blooms are key contributors to the regulating services in the Arabian Sea. Such blooms are most often harmful to the ecosystem and at times to humans too (Fig 2).

Under the ongoing MLR scheme, Padmakumar et al., 2012 in their study, ‘Is occurrence of Harmful Algal Blooms in the Exclusive Economic Zone of Indian on the Rise?’ published in the International Journal of Oceanography, reported 80 incidents of algal blooms from the Indian EEZ during the period 1998-2010. They further noted an increase in the frequency, intensity and spatial extent of blooms in the Indian EEZ. Harmful algal blooms

can alter the biogeochemistry of oceans locally, through the deposition of particulate organic matter (POM) which can accelerate the process of denitrification. Several incidence of human and fish mortality and incidences of release of foulsmelling gases associated with such blooms are also reported from the west coast of India.

The first report of paralytic shellfish poisoning in 1981 was by Devassy and Bhatt in 1991 from coastal Karnataka and Maharashtra. Another outbreak occurred near Mangalore in 1983 following the consumption of clams. Death of 7 persons and hospitalisation of over 500 people following the consumption of the mussel occurred near Trivandrum, Kerala in 1997. Unusual nauseating odour emanating from coastal waters was recorded by the MLR group along the Kollam-Vizhinjam sector of Kerala coast in 2004 and again in 2011. Several people were affected with nausea and breathlessness for short durations.

Ecosystem Cultural Services These are non-material services in the form of scientific discoveries, ecotourism etc. The MLR surveys in the Indian EEZ have led to the discovery of several new species, that are new to science. These include deep-sea brittle star, Asteroschema sampadae from the continental slope of the southern tip of India, a new species of deep-sea shark, Mustelus mangalorensis, from 200 m depth off Mangalore, a new species of deep-sea polychaete Pettibonella shompens from off Car Nicobar Island and another new species of polychaete Palmyreuphrosyne indica from 100 m depth off Car Nicobar Island.

Similarly good prospects for developing benign ecotourism on marine dolphins off the Kochi and Mangalore coasts has been documented under the marine mammal surveys conducted as part of MLR Programme. Kochi bar mouth area accounted for almost 89 per cent of dolphin sighting (coastal waters) having several schools of the species Sousa chinensis. To meet the growing demand on marine fish, fishery on alternate sources such as myctophids, squids and deep-sea fishes need to be promoted. Being shared stocks, regional cooperation amongst Arabian Sea rim countries need to be established for managing these high sea resources for which India should take the lead.

The authors are director and project scientist respectively, from the Centre for Marine Living Resources and Ecology, Ministry of Earth Sciences. sanjeevanmoes@gmail.com Geography and You  july - august 2013  61

C oncept counter

Geogr a phic a l K now l edge t hrough

Quantitative Methods 62  july - august 2013  Geography and You

quantitative methods in geography and its broad distinctions have been discussed in the ESSAY—with a focus on the mapping of geographical distribution.

NIGHT VIEW OF PLANET EARTH. Photo courtesy: NASA

Such a r i ta Sen

Geography and You  july - august 2013  63

T

he teaching and student communities are in the business of producing knowledge continuously, irrespective of their disciplines. They directly do so when they are engaged in research; but also when they are teaching and learning as each individual understand and transmit knowledge in a manner unique to themselves. What do we exactly strive to do when we produce knowledge? Attempt to understand reality? That is a bit tricky, as there is no one version of ‘reality’.

Let me start with a little story...

I had nearly completed my course, Economic Geography, for the semester. Both the students and the subject are close to my heart, and as I was winding up, I thought I would decidedly miss both… for at least a year, at any rate, till the next batch came. A Chinese student, a charming boy, offered me some snacks from his country, something that looked like fried weeds. I popped it into my mouth, quite enjoying the crunch and thanked him when the others signalling from the back caught my attention -‘Ma’am, that’s a fried insect!’ I somehow managed a smile and hurriedly swallowed a gallon of water to get rid of the taste in my mouth.

Thus there were, most certainly, two realities.

One, I liked what I ate when I did not know that

it was a fried insect. Second, I was repelled once I knew what it was! In other words, two different realities were experienced by the same person.

We can term the first reality as experience and the second one as agreement reality. The agreement realities are those learnt from secondary knowledge sources. For example, we may not have actually seen the location of China with respect to India, but from the atlas shown to us in the early years of school, we have learnt that the former is located north of India. In our story, I felt repelled as I am conditioned to believe that eating insects is unacceptable, whereas my dear Chinese student has grown up seeing people around him doing just that. Most of our knowledge typically stems from agreement reality.

Quantitative against the Qualitative

Once we accept that there could be different versions of reality, it would be logical to argue that to a large extent, the methods that we use to achieve our objectives in research shape our understanding of realities. The qualitative-quantitative distinction in geographical research has led to protracted debates with the proponents of each arguing in favour of the superiority of their data over the other. Users of quantitative approach contend that their data is ‘hard’, ‘rigorous’, ‘credible’,

Fig 1: Normally Distributed Data Female Literacy, India 2011

Mean ± Standard Deviation Method

Literacy

Literacy < 46.00 66.00 78.00 >

No. of Division

- 44.00 - 58.00 - 71.00 - 85.00 - 85.00

No. of Division

< 44.00 58.00 71.00 >

Female Literacy Rate

64  july - august 2013  Geography and You

Female Literacy Rate

- 46.00 - 66.00 - 78.00 - 90.00 - 90.00

Map Inputs: Ashwani Parmer

Equal Distribution or Range Equalisation Method

and ‘scientific’. The qualitative proponents counter that their data is ‘sensitive’, ‘nuanced’, ‘detailed’, and ‘contextual’. There is, however, a fuzzy boundary between quantitative and qualitative data. On the surface, the distinction is that the quantitative methods use numbers while the qualitative methods use narratives, attributes, case histories and the like. However, numerical data can be converted into an ordinal scale like high, moderate, low or better and worse, while qualitative information like yes and no or white and black can be coded numerically as 1 and 0 or 1 and 2 respectively. The two approaches however, are different. The broad differences are given in Table 1. In this series, we elaborate selected quantitative concepts, the first of which is geographical distribution.

Conceptualising Distribution

Location is one of the basic concepts that geography uses and often, provides the starting point for any geographical analysis. The response that the question ‘where did it happen’ would elicit either an absolute (specific latitude and longitude location) or a relative (I am located 110 km west of Chilka Lake) response. Geographers use the concept of location for grouping information into manageable units, and give it the name of a region. A region can be defined as an area that

has consistent and/or easily recognisable features that differentiate it from other regions. The scale of regions can vary greatly; compare, for example, Sundarban and coastal plains of India. Most of the events, objects or attributes that geographers study can be found in more than one location or region and this in totality is known as spatial distribution.

Distribution refers to the way an object or attribute is spread out or arranged over geographical space. The concept of distribution can be applied to nearly everything on earth, from animal and plant species, to disease infections, weather patterns, man-made structures, aspects of the economy and society. Many of the phenomena that geographers study are found in some places, but not in the others and are termed as ‘spatial patterns’ of distribution. Geographers started out with identifying these patterns at different scales.

However, a distribution that would make sense in a small scale may not vary at all in a large scale. For example, while normal air pressure distribution could logically be studied at an all India level, it will make little sense to analyse this at district level.

The distribution of an element does not tell us anything about why this pattern exists. However, the distribution of a related phenomenon might give us a partial answer to this question. For example, if we map annual rainfall and share of area under

Natural Breaks (Jenks) Method

Literacy < 53.80 61.15 67.33 >

- 49.00 - 59.00 - 69.00 - 79.00 - 79.00

- 53.80 - 61.15 - 67.33 - 76.38 - 76.38

No. of Division

No. of Division

Literacy < 49.00 59.00 69.00 >

Quantile Method

Female Literacy Rate

Female Literacy Rate Geography and You  july - august 2013  65

Fig 2: Skewed Data Distribution Male literacy, India 2011 Mean ± Standard Deviation Method

Literacy

Literacy < 50.00 60.00 70.00 >

- 54.00 - 65.00 - 76.00 - 88.00 - 88.00

No. of Division

No. of Division

< 54.00 65.00 76.00 >

Male literacy Rate

Male Literacy Rate

rice cultivation, we may come to the conclusion that these two patterns are somewhat related, albeit with aberrations and possibly the former is one of the factors that explains the distribution of the latter.

Some distributions can be seen visually, for example, settlement pattern that we observe from the window of an aircraft when we are descending.

But these visual maps are often not accurate and cannot be stored. This is the reason why geographers are in the business of mapping distribution as the first step in understanding spatial patterns.

Mapping Distribution

This section emanates out of my experience in Table 1: Quantitative vs qualitative approaches Quantitative

Qualitative

Measures objective facts

Constructs social meaning

Focuses on variables

Focuses on interactive processes

Researcher has an ‘open mind’ or is ‘value free’

Researcher has a subjective mindset, rooted in his or her positioning

Independent of context

Authentic or locally contextualised

Many cases

Few cases

Statistical analysis

Thematic analysis

66  july - august 2013  Geography and You

- 50.00 - 60.00 - 70.00 - 80.00 - 80.00 Map Inputs: Ashwani Parmer

Equal Distribution or Range Equalisation Method

the practical classes I conduct in the University and in response to the common mistakes I have seen students committing over the years. There are several methods that can depict distribution (proportional symbol, isopleths, dot, dasymetric maps) but the example that has been taken here is that of a choropleth, more specifically, a chorochromatic method (using hierarchical shades of the same colour) of depicting distribution.

Choropleth mapping shows statistical data aggregated over predefined regions or units, such as countries, states or districts, by colouring or shading these regions. This technique assumes an even distribution over this chosen unit and the degree of saturation or lightness of the shade or the colour is used to indicate quantitative hierarchies of the attribute being mapped.

Dealing with data

The data with which one starts out needs to be made ‘mappable’. For example, the raw population data cannot be depicted in a choropleth map. The reason is that such data is not free of the area effect.

One would expect Goa to have a much lower figure of population compared to Uttar Pradesh since it is much smaller. We therefore need to make data free of the area effect. Typically, we would divide the raw data with a denominator that has an in-built area effect; population needs to be divided by geographical area etc., area under a crop with the total

Natural Breaks (Jenks) Method

Quantile Method

Literacy - 74.00 < 74.00 - 80.00 80.00 - 84.00 84.00 - 89.00 > - 89.00

No. of Division

No. of Division

Literacy rate < - 65.00 65.00 - 75.00 75.00 - 81.00 81.00 - 88.00 > - 88.00

Male Literacy Rate

gross cropped area, hospitals with total population or geographical area—depending on our purpose.

Working with categories or class intervals

The numeric data is typically converted into an ordinal or interval scale such that when one moves up the classes, one can use the term higher or better. Below 50, 50-100, 100-150 and so on applied to a population density data is an interval scale, whereas, low medium and high is an ordinal scale. How does one go about constructing the class intervals? Figure 1 depicts the distribution of female literacy rates, which has close to normal distribution (observe the histogram under each map), with four different classification methods: ■ Equal classes (range/ number of classes), ■ Using the spread of the data to determine the intervals, i.e. mean ± standard deviation (*1, *2.. and so on) ■ Quartile/quintile, i.e. ensure equal number of observations in each class ■ Natural break (find the kinks in the data distribution after plotting a scatter).

Observe that the different methods of classification do not yield very different distribution maps, other than the map using the second method (mean ± standard deviation), which minimises districts under the highest and the lowest class.

This is so because typically, in a perfectly normal distribution curve only about 32 per cent of the

Male Literacy Rate

observations fall beyond mean ± 1 standard deviation. Fig. 2 depicts distribution of male literacy, which is characterised with skewed data (see histograms below the maps). The positively skewed dataset in this set of figures yields vastly different results and the mapping undertaken with the first and second method to a large extent overemphasises the number of district falling in the two highest classes, whereas the third and the fourth map produces an even distribution.

It is important to remember that none of the maps are incorrect, though they are different. The best option would depend on the purpose of the researcher. For example, given that male literacy is far ahead of female literacy, if the Planning Commission of India wanted to identify the poorest performing districts, the second method may be appropriate, whereas if a geographer wanted to regionalise to derive a sense of the social map of India, the third or the fourth method may be suitable. It can be understood from the distribution of female and male literacy that these two phenomena are distributed unequally, the former more than the latter. The following article of this series would deal with the related concepts of spatial concentration, dispersion and inequality.

The author is associate professor, Centre for the Study of Regional Development, School of Social Sciences, Jawaharlal Nehru University, New Delhi. ssen.jnu@gmail.com Geography and You  july - august 2013  67

I ndia outdoors

Kanchenjunga

Cheated Me

Sunrise at Tiger Hill, 13 km from Darjeeling was an experience to remember—for all the wrong reasons...

Sulagna Chattopadhyay

A view of Darjeeling with a cloudy glimpse of Kanchenjunga at the backgound

68  JULY - August 2013  Geography and You

Geography and You  JULY - August 2013  69

N

o way were we going to sight the highest peaks on planet earth—the clouds were just too overpowering. Yet, the stony faced driver's insistent ringing at 3 am pushed us out of bed to confront the cold fog outside. "What are our chances?" I asked, staring at a white wall before the windshield incredulously.

"There is always an element of surprise" retorted the local driver, falling back into his characteristic silence, uncommunicative and unhelpful.

Kanchenjunga, the world's third highest peak, shaking off the darkness to cover itself in the gold and orange of a fresh dawn is an awe inspiring vision we were told. Tiger Hill, a UNESCO world heritage site, situated at an altitude of 2590 m (8482 ft) and 13 km from the town of Darjeeling, is the place to be to 'enjoy' the magnificent view of the sunrise; and, on a perfect day, Mount Everest, too rolls into view—but we were not looking for perfection, just the ordinary.

The car sped through the haze the first 15 minutes and thereafter began our crawl to the finish line, up above the mountain, with roads that could be better off named 'muddy pot holed tracks'. As we edged closer, a good hour later, soft rain started blotting our view—whatever little that we had of the road and the red tail lights of the cars that were before us. The Tiger Hill check post arrived at last...3.56 am...rain stronger...winds stronger... fog thicker...."What are our chances" I screamed over the pattering rain on the tin roof to catch the attention of the old man at the check post ticket counter. " Your luck, madam," he replied in studied sulkiness and handed me the tickets.

The view is splendid-most at around 4 am we were told. The sunrise point in fact offers many other delights for the adventure minded and one can trek downhill to visit the Senchal Wildlife Sanctuary, and its two artificial lakes that serve as a reservoir for supply of water to Darjeeling town.

We were set to make all of that a reality.

Beyond the check post we found cars parked in precarious angles all along the edge of the road leaving less than 6 to 7 ft across for other cars to manoeuvre their way up. After a point even that became an impossibility as we were wedged between cars on all sides. The driver switched off the controls, yanked the handbrake and asked us to take a walk to the observation area—just round the corner he said. It was a good km uphill, tiring us as we hurriedly puffed up through parked cars, 70  JULY - August 2013  Geography and You

braving the cold fog and rain. Watery coffee was pushed into our unwilling hands by local vendors, most of them being women, making quick sales amongst the thousands of tourists who had gathered here. Two beefy men manned the gates of the observation area that bears resemblance to an unfinished glass-house. In accomplished rudeness they demanded our tickets and, as I fumbled to locate them, shoved us to one side to let the others pass. Controlling my temper, and swallowing the disappointment of the still continuing bad weather, we walked up the stairs to the area that our tickets made us eligible to. For Rs 40 we could sit on plastic chairs in hall the size of a basketball field.

The next and highest category is Rs 50 having only 40 seats which were apparently 'sold out'. It was well beyond 4 am and as the clock edged towards 5, I began to consider leaving. The damp cold was now chilling my feet, especially with almost every second pane missing in the windows—making the hall draughty with rain lashing in spasmodically.

Little kids, honeymooning couples and holidaying families huddled together to keep warm as they were totally unprepared for such an onslaught. A skirmish broke out for a seat sheltered beyond a particularly foul location, which died out just as quickly as it had begun. At about 5 am a middleaged man walked to the head of the hall and began addressing the crowd. It is raining he said, but still you should stay put till 6 am or more, as the weather may suddenly clear out, and many people have had astounding sighting and so on and so forth. Then again, he said holding a package high up for all to see, there are CDs available at a certain cost that would give you a feel of what a delight Tiger Hill is. As the toddler enveloped in his mother's arms whimpered in the cold once again, we gave up the search for the elusive mountains and walked out.

But, even though we left the hall there was no way that we could leave the Hill behind to reach the warm haven of our rest house. The cars jammed the roads and we had to wait for nearly two hours before we could even move. So then, I was not 'lucky' and yes I was 'surprised', not with the beauty but with the cheating that the State tourism department indulges in. In one day more than 2000 tourists visit the location on an average all through the summer from March to May after which the monsoons set in making the hills a less prominent attraction. But, has sighting got anything to do with luck? In that case why do we not leave monsoon

Dilapidated ticket kiosk at the entry gate to Tiger Hills. Notice that there are no advisories weather or otherwise.

forecast to luck too, instead of investing hundreds of crores in it. With weather forecast technologies reaching us real-time who are the State authorities fooling? Not one informed response lay in the official website/tourist advisories in the town, with the conniving drivers or the ticket collectors. The Authorities should have closed counter declaring that sighting the Kanchenjunga would be a near impossibility on such and such day—and even if one did sight it, it would be too transient. The weather and temperature advisories would have saved hundreds of tightly scheduled tourists from India and abroad, the harassment of wasting a whole day or very nearly falling ill in a destination like Darjeeling (as you just too tired to do anything after sleep deprivation, disappointment, not to mention the cold) and made the destination

memorable for all who would find an opportunity to visit it in perfect weather.

Thinking from another perspective, I began to wonder what would have been my plight if I needed to seek any emergency medical care in a scenario where not a single car could move for over two hours. What the State tourism authorities feel about this will remain a mystery however, as G'nY correspondents were unable to ferret out a response from them. Even if by conservative estimates two lakh tickets are sold over three months, the Tiger Hill sojourn makes about Rs 60 lakhs for its keepers in one season. Surely that should be enough to maintain the road and a few glass panes.

Cheating our fellow countrymen with CDs instead of the real thing is hardly what we expected would happen in the Queen of the Hills - Darjeeling.

Geography and You  JULY - August 2013  71

I ndia outdoors In violation

The Jhora of Sikkim

The Urban Development and Housing Department, Govt. of Sikkim, under the Sikkim NonBiodegradable Garbage (Control) Act proactively announced in 1997 that "no one is allowed to throw bio-degradable or nonbiodegradable garbage in any public place or in any drain ventilation shaft pipe and fitting connected with the private or public drainage except in appropriate garbage receptacles.

Any one violating this is punishable with imprisonment for a term which may be extended to six months or with a fine up to Rs 5, 000 or both". But the contradiction is visible. Sikkim having a very high water table, abounds with many gushing streams, locally identified as jhora. In and around Gangtok, the jhora are marked with bold signage that garbage disposal in such locations is a punishable offense but the reality is quite opposed. And this is only about solid waste disposal—the overflowing sewerage and the stench of the dirty water calls for a third party assessment to derive the level of the pollution in the groundwater of Gangtok region.

72  JULY - August 2013  Geography and You

Future earth

Action for Protection of Wild Animals, organised the event with over 520 students at several schools in Pattamundai, Odisha.

Hamraah Foundation organised a rally at Navjyoti Sr. Sec School, Gannaur, Sonepat with around 720 participants.

The Ministry of Earth Sciences (MoES) sponsored 62 organisations across India to celebrate Earth Day on 22 April with a view to spread awareness about preserving planet earth. Schools, colleges, universities national laboratories, educational institutions, and NGOs organised various competitions viz. poster making, slogan writing, debating/ elocution apart from seminars, talks and more under the theme Future Earth.

Lokamata Rani Rashmoni Mission organised a drawing competition in many schools in West Bengal involving around 2180 participants.

OASTC, IIT, Kharagpur organised the celebrations at their Institute where around 1210 people were involved in the programme.

Progressive Action for Community Emancipation, organised celebrations at Sri Gnanambica Degree College, Chittoor, Andhra Pradesh, involving over 340 participants.

Andhra Pradesh Environmental Education Centre held the event with over 410 participants at SPHMD College, Machilipatnam.

Future earth

Peopleâ&#x20AC;&#x2122;s Participation organised the event at several school in Hooghly, West Bengal.

Around 11941 participants were involved in the programme.

Samanta Chandrasekhar Vigyan Club organised a drawing competition at various schools in Balasore, Odisha. The event saw many participants actively involved.

Sanjeevani Foundation organised Earth Day celebrations at Rajkiya Prathamik Vidyalaya, Jodhpur. Tree planting was also undertaken by the participants.

Aabahana organised the Earth Day celebrations at various schools in Nairi and Baulabandh, Odisha. Around 1000 students and teachers participated in the rally.

Commercial Agriculture and Rural Area Development Agency organised the event at various schools in Kalahandi, Odisha. Around 5140 students participated.

The Creative Centre for Rural Development organised a seminar at St Paulâ&#x20AC;&#x2122;s Senior Secondary School, Palampur, Himachal Pradesh. Around 300 participated.

Millennium India Education Foundation organised the event at Mount Abu Public School, Rohini and Vishwa Bharati Public School, Noida. Over 350 participated.

Himount Samitee organised street plays at Tehsil Mukhyalay Pokhri, Chameli, Uttarakhand. Around 500 participants were involved in the programme.

Aqua Foundation organised a painting competition at Ryan International School, Gurgaon. Around 3600 participants were involved in the programme.

Janajagaran Kendra organised a debate competition at various schools at Dhenkanal, Odisha. Around 1680 participated in the programme.

Society for Promotion of Science & Technology in India organised tree planting at TIT Senior Secondary School, Bhiwani, Haryana. Around 600 participants were involved.

Indian Environmental Society organised the Earth Day celebrations at Wetland Club School, Udaipur, Rajasthan. Around 200 participants were involved in the programme.

Science & Technology Educators Forum organised the Earth Day celebrations in Samastipur, Bihar. Around 700 participants were involved in the programme.

India International Intellectual Society organised the Earth Day celebrations at Kanya Mahavedilya College, Karkhoda. Sonepat with around 400 participants.

Heart Care Foundation of India organised the Earth Day celebrations at Delhi Public School, Mathura Road, New Delhi. Around 3030 participants were involved in the event.

Learning in Geography, Humanities Technology and Science (LIGHTS), New Delhi organised multi-activities in 25 schools.

Around 26250 students participated.

Future earth

All India Foundation organised the event at SGTB Khalsa College, University of Delhi.

Around 350 participants were involved.

Advancement of Peoples Group organised the drawing competition at various schools in Assam. Around 4500 students participated.

Delhi Public School organised the Earth Day celebration in their premises, Greater Noida.

Around 2800 participants were involved.

Environ Friend Institute organised a quiz at Kandicli, Mumbai with many enthusiastic students from senior classes.

Peopleâ&#x20AC;&#x2122;s Welfare Voluntary Organisation Centre held the event at Anchalika High School, Deuli involving 1350 participants.

Sharda University celebrated the Earth Day at School of Engineering and Technology, Greater Noida with around 1050 students.

Arth Society for Welfare of the Mankind organised street plays at Pithoragarh, Uttarakhand involving 12520 participants.

Brown Hills College of Engineering and Technology organised the event at Dhauj, Faridabad involving 3200 participants.

The funded organisations held activities like planting trees, city cleaning and cycling. Over a lakh people participated in all from more than 40 cities across the country in the 2013 celebrations. The painting competition was to be mandatarily organised where various levels were ascertainedâ&#x20AC;&#x201D;1-5; 6-11 and 12 to graduation in order to cover children of all age groups.

IREDA

v{ k

l dk

tkZ ls ns'k fo ;ร

xkยกo&xkยกo fctyh] ?kj&?kj izdk'k