Dur-e-shahwar Khahil. Delta Archipelago-Indus Delta, Pakistan

DELTA ARCHIPELAGO INDUS DELTA | PAKISTAN

DUR-E-SHAHWAR KHALIL

MASTERS OF URBANISM AND STRATEGIC PLANNING KU LEUVEN

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DELTAS IN CLIMATE CHANGE DUR-E-SHAHWAR KHALIL NAOMI THIRU

Thesis submitted to obtain the degree of Master of Urbanism and Strategic Planning Promotors: Bruno De Meulder Kelly Shannon

Academic Year 2017-2018 Master of Urbanism and Strategic Planning 3

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PART 01

DELTAS IN CLIMATE CHANGE

AUTHORS DUR-E-SHAHWAR KHALIL NAOMI THIRU

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CONTENTS DELTAS IN CLIMATE CHANGE

TANA RIVER | INDUS RIVER

RISING TEMPERATURES

RISING SEA LEVELS THE TANA DELTA | THE INDUS DELTA LIVING IN DELTAS WITH CLIMATE CHANGE

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DELTAS IN CLIMATE CHANGE

TANA DELTA KENYA

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INDUS DELTA PAKISTAN

Deltas are areas of high biodiversity, and provide a large variety of habitats, ecosystem, goods and services. Major deltas harbour fast growing populations, and are important economic hubs with intense urbanization, industrialization and agriculture. As a result, most deltas have experienced intense transformation with significant loss of biodiversity due to direct human activities (Vergas-Vilarrubia 2016).

This has contributed to their increasing vulnerability.

This vulnerable state of deltas makes them particularly susceptible to climate change. According to the Intergovernmental Panel on Climate Change IPCC, the scientific evidence for warming of the climate system is unequivocal. The current warming trend is of significance because most of it is extremely likely (greater than 95 percent probability) to be the result of human activity since the mid-20th century and proceeding at a rate that is unprecedented over decades to millennia. (https://climate.nasa.gov/evidence/) Both the Indus and Tana deltas have shown similar deteriorating environmental conditions. Climate change is projected to create both greater drought risks and more extreme flood risks, and this has already begun to be felt in both the Tana and the Indus deltas.

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TANA DELTA KENYA

Kenya lies on the eastern coast of the African continent with the Equator bisecting the country into two almost equal parts. Most of the country lies within the eastern end of the Sudano-Sahelian belt, a region often affected by drought and desertification in Africa.

In Kenya, the climatic factor of greatest economic significance is rainfall, the distribution of which is irregular.

The climate is characterized by wet and dry seasons with annual rainfall ranging from 250 to 2500 mm.

Only 15% of the country receives rainfall over 750mm per annum, and the catchment areas that receive over 1250mm being even smaller. (Kenya, a natural outlook).

Kenya is already experiencing climate-related events, with changing rainfall patterns putting the country at most risk to changing environmental conditions that will greatly affect livelihoods. Although the rains are experienced in two distinct seasons, they are erratic in both temporal and spatial terms.

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The temperatures are relatively high and account for annual potential evaporation, which is often above 2,500 mm.

Illegal logging, clearing forests for agriculture and uncontrolled settlements in the water catchment areas of Kenya are the main human activities that compromise the source waters of the Tana River. The growing intense use of the waters of the Tana river upstream for power production and a shift from rainfed to irrigation of agriculture lands increases the fragility of the delta as the most important resource, water, is reducing. Drought conditions have been experienced in 1975, 1976, 1980, 1981, 1983, 2001, 2004, and 2009 where the Central and North regions of the county are the most prone, while areas along the River Tana are more prone to floods. Flood events in the county include those of 2002, 2003 and 2010 and the recent flood events of 2018 led to internal displacement of people and destruction of roads (Climate Risk Profile Tana River County, 2016).

Tana River county, where Tana Delta is situated has relatively hot and dry climate. It experiences heat stress, dry spells and drought which contribute to agriculture and livelihood risks in the county. Due to desertification, there is a reduction in the natural resources that support livelihoods in many areas especially the arid and semi-arid areas, (also referred to as drylands), the delta has become a lifeline for an increasing number of humans and animals.

INDUS DELTA PAKISTAN

Pakistan is particularly vulnerable to climate change because it has generally a warm climate; it lies in a geographical region where the temperature increases are expected to be higher than the global average; its land area is mostly arid and semi-arid where threefourths of the country receive rainfall of less than 250 mm annually, except in the southern slopes of Himalaya and the submountain region in the northern segment of the country, where annual rainfall ranges from 760 mm to 2,000 mm. The country receives rainfall through summer monsoons and winter Western Depressions.

In the past decade, recurrent spells of extreme weather events such as floods, droughts, glacial lake outbursts, cyclones, and heat waves have taken a heavy toll on both life and property which has adversely affected the country’s economic growth.

Being the sixth most populous country in the world, the demographic trends are also greatly stressing natural resources of the country most importantly water, making Pakistan one of the most water stressed countries.

The climate change projections of the AR5 for South Asia as a whole show that warming is likely to be above the global mean and climate change will impact the glaciers’ melting rate and precipitation patterns, particularly affecting the timing and strength of monsoon rainfall. Consequently, this will significantly impact the productivity and efficiency of waterdependent sectors such as agriculture and energy.

The transboundary Indus basin covers 65% of the country’s total area. The Indus Basin Irrigation System is the world’s largest contiguous irrigation system, accounting for 95% of the country’s total irrigation system.

The province of Sindh were the Indus Delta is located has a long history of droughts which persisted over a stretch of atleast couple of years (Memon, 2005). For instance, 196869, 1971-74, 1985-87 and 1999-2002 are known for their damages to crops, livestock, soil and natural ecosystem in addition to massive migrations increasing pressure on marginal natural resources in surrounding areas.

The super floods of 2010, were the result of a rare interaction of three weather events resulting in intense rainfall. Poor slope of land, heavy soil and abandoned drainage infrastructure, dam/barrage related back water issues aggravated the situation and caused great damage.

Indus Delta is a vast fertile plain located in climatically arid zone of intense heat and highly variable annual rainfall (Rasul et al., 2012). It is affected by all changes in the sea and land due to global warming. All Anthropocene changes in the north of the Indus directly affect the Delta.

All sea-related weather events also affect it, directly influencing the life of delta dwellers (Rasul et al., 2012).

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RISING TEMPERATURES

DESERTIFICATION IN KENYA

Desertification is a complex physiographic process caused and accelerated either by natural or maninduced factors. The natural causes of desertification are mainly related to climatic peculiarities and condition, such as extreme aridity, uneven distribution of precipitation throughout a year and its variability from one year to another, frequent recurrent of drought, low air humidity and or high values of temperature.

In broader term, these would include overgrazing, deforestation, poor land management and policies among others. All these lead to the reduction of quantity and deterioration of the quality of renewable natural resources such vegetation, soil, water and changes in fauna. (Nguru and Rono 2013)

Climatic variation is the main cause of droughts in Kenya. According to the Intergovernmental Panel on Climate Change Third Assessment Report, 2001, climate will be associated with rise of mean temperatures by the year 2025. These are the conditions facing the ASALs of Kenya. These drylands are rapidly changing to the detriment of the environment. Increased number of livestock owned by migrants into ASALs has reduced their the carrying capacity. Perennial grass cover has decreased whereas annual grass, woody cover and the amount of bare ground have increased.

The Tana river and delta is of great importance to the country, and more so to the ASALs because it is the main source of water for the populations of these areas. Following the increasingly drier conditions in the region, there is increasing migration of people and their livestock to the delta in search of more sustainable pastures. (Nguru and Rono 2013) World Arid Semi-Arid Lands https://pubs.usgs.gov/gip/deserts/what/world.html

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HIMALAYAN GLACIERS’ RETREAT Himalaya-Karakorum-Hindukush together makes the largest mountain chain over the earth and they are custodian of the third largest ice reserves after the Polar Regions. They possessed a treasure of solid water which melts with high temperature in summer and makes this precious resource available in rivers (Salman, 2010). Rivers such as the Indus, the Ganges, and the Yangtze are fed by the runoff from the glaciers of these ranges which serve as the lifeline for more than a billion people in Asia. Since temperature maxima have been increasing at a greater rate, the thinning of ice and retreat of glacial extent has taken place simultaneously at an alarming rate. The decay estimates calculated by remote sensing techniques show that Siachen Glacier has reduced by 5.9km in longitudinal extent from 1989 to 2009. Thinning of ice mass is evaluated 17% (Rasul, Mahmood, Sadiq, & Khan, 2012). https://www.treehugger.com/clean-technology/then-andnow-photographs-document-stunning-melting-of-himalayanglaciers.html 13

RISING SEA LEVELS

Sea level has been rising over the past century, and the rate has increased in recent decades. In 2016, global sea level was 3.2 inches (82 mm) above the 1993 average— the highest annual average in the satellite record (1993-present) Sea level continues to rise at a rate of just over one-eighth of an inch (3.4 mm) per year, due to a combination of melting glaciers and ice sheets, and thermal expansion of seawater as it warms. From the 1970s up through the last decade, melting and thermal expansion were contributing roughly equally to the observed sea level rise. But the melting of glaciers and ice sheets has accelerated, and over the past decade, the amount of sea level rise due to melting—with a small addition from groundwater transfer and other water storage shifts—has been nearly twice the amount of sea level rise due to thermal expansion. (www.climate.gov)

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The Tana delta lies in one of the world’s macrotidal zone and is exposed to a tidal range of up to 4 meters. Given the morphology of the delta, this puts the lower floodplain at great risk of complete inundation in the event of a storm surge. Reduced flows of water have already put various streams of the ocean into the ocean into disuse except during periods of flooding. These channels have now become areas of sea water intrusion. Sea water intruding into deltaic channels has already led to the saline intrusion, which is set to moving inland at the expense of freshwater habitats. A system of coastal dunes, punctuated by old river channels, rising to 20m along the coastal strip of the delta currently create a natural barrier protecting the lower floodplain from the sea.

These dunes however are also at risk of coastal erosion.

Due to increased frequency of storm surges in the Arabian Sea combined with the sea level rise, the sea water intrusion into the Indus Delta has become an emerging challenge which would claim more land area (Chandio et al., 2011) with the passage of time. This has greatly increased the saline content of soil in the Delta, projected to rise to such a level to completely deteriorate productivity of fertile soils. This threatens natural habitats along the shoreline and a shift in biodiversity due to the overriding push of sea water. The loss of discharge has further caused the delta to become a transgressive sand body, dominated by wind-blown sand deposits(Wells & Coleman, 1985).This has lead the delta forming the morphology of a wave dominated delta.

As the controlled upstream diversions of the river for irrigation has resulted in the river reaching the sea through only two creeks, the rest of the river outlets becoming sea water creeks. During certain periods of the year, water has not reached the sea any more, making it a closed basin (Molle et al., 2010). Increased stormy conditions in the north Arabian Sea has given rise to the enhanced tidal activity. Along the coast line, increased to- and fro motion of tides and waves continue encroaching the shoreline posing threats to agricultural land, infrastructure and development activities (Rasul, Mahmood, Sadiq, & Khan, 2012).

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NEGLECTED TAIL-ENDS

During the colonial times when Kenya was under under the guise of enhancing food security for the the British rule, the capital city of Nairobi, the country. Also, the big corporations interest in the central highlands and Western parts of the country delta sidelines the needs of the delta communities. were given priority in the allocation of resources for development. Together with the arid northern parts of Kenya,the Tana delta area became one of the neglected regions and has since then slowly fallen out of the productive network of the country despite it’s high productive potential. It has poor infrastructural connections to major towns and poor provision social services for the communities that live there.

In the last few decades, new interest has been generated in the delta regions for the development of large scale irrigation projects which have proven to be poorly conceptualized as the delta dynamics are not fully understood. The region is viewed as a vast empty wetland that needs to be exploited

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2X660 MW IMPORTED/THAR COAL POWER PROJECTS AT KETI BANDER

E Street,

The Delta as the southern most part of the country and also the ending of the River Indus meant that it was a waste land. The river lost its value SINDH COAL AUTHORITY as a source of water as it flowed southwards ENERGY DEPARTMENT and all water that is let flow through the last unused and uncaptured, as wasted GOVERNMENTbarrage, OF SINDH water. The southern province of Sindh has always Bungalow complained No.16 about a lack of water available for the tail end of agriculture which falls in the delta.

Zamzama Park, DHA Phase-V, The delta never sawKarachi. the implementation of a large project except for the making of the bunds Phone: 99251507 that control the river. Projects that were planned included making a large city over a protected area of mangroves, big port cities with industrial1 area and coal processing power plants at the edge of delta and a seawall running parallel to the edge of

the delta to curtail sea water intrusion.

These projects have only been talked about rather than planned and implemented. But with recent Chinese investments in the country in the making of a new Silk Route, these projects may come to the fore.

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TANA DELTA KENYA

The delta ecosystem is highly dependent of the Tana River . Waters from the Tana bring with it alluvial sediments, and water that replenished the lakes, farms and floodplains.

As a vast alluvial floodplain flanked on either side by terraces, it is a mosaic landscape that supports a wide range of flora and fauna.

This landscape is home to some of Kenya’s minor indigenous communities, who have depended on it for centuries. In recent times however changing climate and increasing populations has made the delta resources more scarce. Changes in the river’s hydrology can also be directly attributed to human activity upstream, that have led to reduced water flows that have turned the delta into a less productive, high potential landscape.

The Tana is the major shared resource in the delta by farmers and pastoralists. The river simultaneously brings the communities together and separates them both physically, as a barrier between settlements, and culturally by the different community needs for the water. This has resulted in violent conflicts erupting between the delta communities.

This thesis is a spatial exploration of the delta and its resources, as pertaining to settlements and the communities that depend on it, and explore how this drastically changing environment can be regenerated, and hence create better living conditions. It attempts to explore how urbanism can address the conflict through a thorough study of the spatial elements of the landscape and the interplay between natural and human dynamics.

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INDUS DELTA PAKISTAN

With the already manifested and the impending affects of climate change on habitats like the deltas, we see events like floods which have devastating effects on crops and agriculture and human settlements and infrastructures.

The exploitation of natural resources and a need to control natural processes to obey to human demands has led to events like the super floods in 2010 in Pakistan, which following their original natural rhythms cause destruction to “encroaching” human activities.

In the specific context of these events, to the Indus Delta and Pakistan, the question then arises of how these settlements and agriculture, which is a backbone of the economy, can exist with natural processes such as flooding.

Exploring the natural process of avulsions specific to the Indus Delta, the thesis attempts to propose a way to look at floods as a natural process of a river and to work with these processes. While learning from the landscape rhythms of the delta, a new vision for the delta area is proposed by reinforcing landscape structres that inform agricuture activity and settlements in the area.

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PART 02

INDUS DELTA ARCHIPELAGO

AUTHOR DUR-E-SHAHWAR KHALIL

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CONTENTS 01 NATURAL INDUS

FROM THE HIMALAYAS TO THE ARABIAN SEA

PRE 1869 INDUS DELTA

TRAVERSING THE DELTA AVULSIONS

INDUS AVULSION

SHIFTING LANDSCAPE OF THE DELTA 02 ENGINEERED INDUS DAMS/BARRAGES/CANALS

ANTHROPOCENE INDUS DELTA

WATER AND SEDIMENT FLOW

DISTRIBUTING WATERS BUNDS KACHA

VEGETATION IN THE DELTA

DRAINAGE STRUCTURES

LEFT BANK OUTFALL DRAIN DHORAS

03 NATURAL + ENGINEERED INDUS FLOODS

INDUS AVULSION-FLOODS 2010

REINSCRIBING THE NATURAL “DHORA”

THE BRAIDED “DHORA”

DELTA ARCHIPELAGO

SEASONAL FLOOD CYCLE OF THE INDUS

INDUS IN HIGH FLOODS

VEGETATION IN THE “DHORA” SUJAWAL

THE FLOODED CITY THE ISLAND

THE ISLAND IN AVULSION DHORA VEGETATION

FRAMES FOR URBAN DEVELOPMENT CONCLUSION

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01 NATURAL INDUS

FROM THE HIMALAYAS TO THE ARABIAN SEA

The Indus floodplain is between 100-200 km wide and consists of deposits of unconsolidated and highly permeable alluvium deposited by the Indus River and its tributaries (Kazmi, 1984). The lower alluvial plain and delta received between ~300 and 1100 Mt/y of deposits during the Holcene which were delivered by the Indus River (Clift and Giosan, 2013).

The Indus River also known as the “Sindhu” in local language is one of the longest rivers in Asia. It runs 3000 km through Pakistan. It originates in the mountains of the Himalayas near Tibet, draining an upper basin that lies across western Tibet, the Himalaya and the Karakoram. Some of its upper course runs in India but most of its basin and channel lie in Pakistan. The Indus is sourced at 5182 m elevation, on the northern slopes of Mount Kailash in the Gangdise Range of Tibet near Lake Mansarowar, close to the source of another major river, the Brahmaputra. A large load of sediments from the mountains is carried down the river. It flows through the mountains to the densely populated and widely cultivated lands of Punjab (Inam et al., 2008).

The valley and delta of the Indus, occupying a depression between hills of Kirthar Ridge in the system of Sulaiman Range and Rajhastan Highland, form a green oasis sharply defined against desertificated bush tropic savannas on the west and the sands of Thar Desert on the east (Kravtsova, Mikhailov, & Efremova, 2009). It flows down the plains of Punjab receiving water from large tributaries, Shyok, Shigar, Gilgit and Kabul in the north and Jhelum, Chenab, Ravi, Beas and Sutlej in the south of Punjab (Inam et al., 2008). The tributaries in the south of Punjab fall into the Indus at “Punj-nad”(locally meaning five rivers). Most of the water in the River Indus comes from the south west monsoon of Asia, during which the river is at peak flow, between June and late September. The 97,000 km2 drainage basin of the Indus ranks the twelfth largest in the world. Its 30,000 km2 delta ranks seventh in size globally (Inam et al., 2008).

The Indus River and its five branches have been cause for contention between the newly formed states of India and Pakistan in 1947. The Indus Water Treaty was drawn up in 1960 to resolves water issues between the two nations.

THE HEADWATERS OF THE RIVER INDUS IN THE HIMALAYAN MOUNTAINS

THE IRRIGATED INDUS PLAIN IN PUNJAB

THE DELTA IN THE SOUTH OF SINDH

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https://photorator.com/photo/33968/indus-river-himalayas-][IMG]https://photorator.com/ photos/images/indus-river-himalayas--33968.jpg

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The reconstructed course of the Indus in the lower plain as it may have existed in the Greek period, 300 BC.

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This content downloaded from 134.58.253.56 on Sat, 05 May 2018 12:02:27 UTC All use subject to http://about.jstor.org/terms

The Lower Indus Plain in the sixteenth century AD.

This content downloaded from 134.58.253.56 on Sat, 05 May 2018 12:02:27 UTC All use subject to http://about.jstor.org/terms

MONSOON/GLACIAL MELT

The Indus is the oldest river in the Himalayan region. It delivers the fifth argest sediment load to the Arabian Sea. The Indus is monsoon-driven and Himalayan snow-fed, and drains an area of 970,000 km2 (Syvitski & Robert Brakenridge, 2013) Historically, its average coastal discharge was ~3000 m3/s; with diversions and agricultural use, this discharge has fallen to 300 to 800 m3 /s with long periods of no flow (Asif et al., 2007) in (Syvitski & Robert Brakenridge, 2013).

Most of the water flow occurs between May and October following the melting of snow in the headwaters of the basin and augmented by summer monsoon rains (Milliman et al., 1984; Karim and Veizer, 2002) in (Giosan et al., 2006).

The delta lying in the South of the country itself receives much less rainfall and depends on the flow of the Indus river which comes from upstream during monsoon. Consequently the lower Indus River has a slow sluggish flow as water is lost via evaporation and water abstraction for irrigation and drinking water.

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PRE 1869 INDUS DELTA

The Indus Delta is the fifth largest Delta in the world.

The Indus has formed a vast deltaic complex in southern Sindh, most of which has been abandoned due to frequent natural channel avulsions (Inam et al., 2008).

Because of the high sea-level stand, the impact of fluvial sediment is not strong enough to maintain a supply of coarse sediment to the deep-sea. The delta extends to the east into the Great Rann of Kutch, a vast mudflat area that is invaded by storm surges during the summer monsoon. The Rann of Kutch is probably a former gulf of the Arabian Sea that has been filled by deltaic deposition (Malik et al., 1999). Over time, the rich flora and fauna attracted settlements directly to the banks of the Indus and also along the numerous canals and distributary channels off it.

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During the eighteenth and nineteenth centuries, large volumes of water and sediment were discharged round the year through the delta. Two river ports, Keti Bandar and Shah Bandar, used to handle all imports and exports between Sindh and Bombay. The coastal agricultural areas near Keti Bandar, Kharo-Chan, and Shah Bandar produced rice which was the main export crop. Seaborne cargo traffic in transit to the upper Sindh was transported by boats. In general, the area was prosperous and the socioeconomic condition of the residents was very good. During the south-west monsoon, the boat traffic remained suspended as the vessels could not enter the delta due to the storminess of the wet monsoon.

The more natural Indus Delta is characterized by high river discharge, moderate tides and high wave energy conditions (Giosan et al., 2006).

The descriptions of the writers on Alexander’s expedition record that the delta was at Patala, where the river divided into two large branches running to the sea. The site of Patala is speculated to be at the present city if Hyderabad or Thatta. The Delta Country as known to the Greeks was Patalene. The Delta in this descriptions was bounded on the east by the sandhills of the desert and on the west by the slopes of the Kohistan mountain range.

This boundary runs south, due west towards Karachi.

This delta region covered nearly 10,000 square miles.

Much of the delta plain is quite arid with swampy areas being restricted to the immediate tidal channels and coastal plains (Inam et al., 2008). The wave power at the delta coast is about 13 J s-1 per unit crest width, the fourth most powerful in the world. It rises to 950 J s-1 (the highest in the world) at the offshore water depth of 10 m (Pakistan Water Gateway, 2003). Offshore, the sediment discharged by the Indus has produced the vast Indus Submarine Fan, about 5 million km3 in volume (Naini and Kolla, 1982). The lower Indus, especially the delta section, carries an extremely reduced discharge and sediment load which at times do not reach the delta shore face. Large changes have taken place in the river in the delta, with it moving westward since about 20,000 years ago. The main channel has shifted four times until it came to its present course.

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[Narrative of a Visit to the Court of ... the Ameers of Sínde, at Hyderabad ... in the year 1827-28, compiled officially for the Government of Bombay,

by James Burnes ... Presented by ... the Governor in Council to the Literary Society.

James BURNES, Physician-General of India.

Edinburgh : John Stark, 1831. http://explore.bl.uk/primo_library/libweb/action/

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The Map of the Indus Delta-South Side 1833

http://4.bp.blogspot.com/-unFU60dSlWU/UjE4RlUmTKI/ AAAAAAAAJBM/7pNLdFVXIRU/s1600/1833%2Bmap% 2Bof%2Bthe%2Bindus%2B delta%2Bsouth%2Bside.jpg

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TRAVERSING THE DELTA

The first accounts of movement along the River Indus within the Delta were from early Greek records describing Alexander the Great’s journey. With a fleet of 1800 ships built in just 2 months and headed for the Indus River and the Indian Ocean. The main part of the army marched along the river keeping pace with the ships.

The main part of is army reached the port of Patala in July of 325 BC. After resting and exploring the new river channels they planned their return to Babylon. 20,000 men then set sail west from the Indus River along the coast to the Persian Gulf (Holmes, 1968). Great docks were built at the Patala and a colony was left behind.

This was the first destination of the ships from the west.

The rest of south India was linked to a road through Ujjiani reaching the port on the mouth of the Indus.

Thatta was the main seaport of the area which was abandoned due to silting of the Indus River(Holmes, 1968). The river was traversed upto this port and then crossed at some point north.

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The increased silting of the main channels of the Indus led to the gradual abandonment of Thatta and Lahori Bandar as sea ports.

In the period of the Mughals a new port was created called “Auranga Bandar”. They shifted trade to new ports of Shabandar and Kharak Bandar but their prosperity did not reach that of Thatta. The period after saw a decline in maritime trade in Sindh.

Links from these ports were made to the rest of the Sindh and the subcontinent.

In late 1720s, as Kharak band declined due to silting, a new port was made in Karachi after 1750.

The mid 18th century Sindh became an important as a crossroads of maritime and land routes.

During the British rule the port of Karachi was then linked by land and rail running parallel to the river to Thatta and then crossing to the left bank and beyond.

The Indus Flotilla Company was established in 1859 to carry cargo through big steamers and barges on the rivers through the country.

It was thought to be a major form of transport for carrying cargo from the Arabian Sea to North Punjab. This was to be linked with rail from Kotri also to the port of Karachi which was being built.

Cargo coming in would be was first unloaded at Karachi and taken through small boats which went though various routes in the Indus Delta to Jhirk south of Hyderabad, where one of the most modern river terminals was made for the Indus Flotilla Company.

In 1859, a railway was constructed between Karachi harbour and Gizri creek on the delta which reduced the journey of small boats considerably. But eventually the current of the River Indus proved too strong for the cargo carriers. (“[IRFCA] The Indus Flotilla Company,” n.d.)

Even at present travel up the Delta from Karachi is on the right bank of the river, with the first major crossing being at Thatta from West to East. Rail links go the same direction at Hyderabad with other web like network spreading through the East of the delta.

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AVULSIONS

AVULSIONS ON THE INDUS

“Avulsion, i.e. the relatively sudden displacement of a river channel, has an important effect on sediment distribution and on the architecture of fluvial deposits because avulsion is a primary control on channel location on a floodplain. Most avulsions occur when a triggering event, commonly a flood, forces a river across a stability threshold. The closer the river is to the threshold, the smaller is the flood discharge needed to initiate an avulsion(Hampson, 1997).

A river avulsion may be permanent without human intervention, and the translocation is not confined to the existing meander belt. It is at least a two-step process: “(1) sedimentation along a relatively fixed channel bed, over many years of time, elevates such above surrounding terrain, and (2) during floods, breaches in banks and levees allow major shifts of the position of the channel and its meander belt to a new, lower, location, perhaps hundreds of kilometers distant” (J. P. M. Syvitski et al., 2013). Decades may be required to accomplish a complete avulsion.

With repeated floods scouring deeply enough to create a persisting new river channel(J. P. M. Syvitski et al., 2013).

All major floods on the Indus River have at some point breached levee systems and have spilled over onto the old river plain. In times of floods breaches have also been intentional to divert the floods to irrigation lands to save settlements from being inundated.

This has been a standard flood control approach even when the area was under British Colonial Rule.

Previous major avulsions of the Indus are documented in history and prehistory, including a river position at B.C. 300 closely similar to that temporarily occupied after the northern avulsion in 2010. Few cities lasted across multiple centuries, inpart because Indus River avulsions commonly left river settlements without water resources for drinking, agriculture or transportation.

Avulsions have also been recorded as destroying ancient cities like the Arab city of Mansura north of the delta.

Schumm et al.(2002) regard the avulsions to be controlled by tectonic activity because they have repeatedly occured at the same location, and levee breaching during significant flood events is thought to be directly responsible for other historical avulsions.

The Indus Delta is a classic example of how the river distributary channels migrated across the delta surface. The channels were numerous and were always mobile (J. Syvitski et al., 2009), feeding an actively prograding tide and wave affected delta(Kravtsova et al., 2009). During the Late Holocene, river avulsions both transient and permanent were normal. Natural avulsions were still occurring in the 19th century (Kravtsova et al., 2009). Against the natural system of the Indus, the distributary channel numbers decreased to 80% by the harnessing of water resources through the extensive irrigation system, capturing much of the water, sediments and nutrients(J. Syvitski et al., 2009).

The former province of Sind, West Pakistan, showing former courses of the River Indus This content downloaded from 134.58.253.56 on Sat, 05 May 2018 12:02:27 UTC

Holmes, D. A., & Geographical, The Early History of Water-Supply All use subjectT.to(2018). http://about.jstor.org/terms Author ( s ): C . E . N . Bromehead Published by : geographicalj Stable URL : http://www.jstor.org/stable/1787344. The Geographical Journal, 99(3), 142–151.

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SHIFTING LANDSCAPE OF THE DELTA “The Indus has always built up its bed and run along broad “ridges” of its own creation till it slips off to one or other side and starts the process anew. The modern contours afford clear evidence of the different courses taken by it over a period of several thousand years”.

Lambrick, H. T. (1967). The Indus FloodPlain and the “Indus” Civilization. The Geographical Journal, 133(4), 483–495. https://doi.org/10.2307/1794477

The first documentary evidence of the Indus in Sindh is provided by the Greeks in 326 BC, the Indus is described as forming two large islands, the south one called Patale. The Lower Sind capital, Patala, lay at the head of the delta, i.e. near the junction of two major delta branches(Holmes, 1968).

At the time of the Arab conquest in the early eight century, the River Indus was crossed at Dahiyat north of Hyderabad which was known as Nerun. The port of Debul at which the Arab army landed is believed to be near Thatta.

Over the next centuries the course of the river shifted laterally north westward. In lower Sindh Thatta was established as the capital in the fourteenth century.

The Indus River silted in the 1600s shifting its course a little eastwards and leading to the abandonment of Thatta as a seaport( Holmes, 1968). In 1758-59 the river adapted its course west of Hyderabad which was built on the site of the river at Nerun. Hyderabad was established as the capital in 1768. South-east Sindh dried up further as a result. There were spillways on

the left bank of the river which were previous courses of the river. The Sujawal area was riddled with many small spillways at the time (Holmes, 1968). The river reached its westernmost limit in the delta, in the sixteenth century moving back eastwards since then.

The Indus river adopted its present course west of Hyderabad in 1758 and the Phuleli a significant discharge branch at Hyderabad thright he first half of the 19th century became a spillway.

The river has a long record of river avulsion and floodplain development and demonstrates how the floodplain aggrades through major avulsions of the trunk Indus (J. P. M. Syvitski et al., 2013).

The Indus River in the Delta has shifted course over centuries from the Thar Desert in the East to the Kirthar Mountain Range in the West. The current river falls through two creeks to the sea. The delta was growing over time since records from 300 BC. It is said to be receding since the 1960s as irrigation schemes were built on the river and water and sediment flow decreased significantly.

Contours of the Lower Indus plain, with some probable ancient courses and branched of the river which they suggest Lambrick, H. T. (1967). The Indus Flood-Plain and the “Indus” Civilization. The Geographical Journal, 133(4), 483–495. https://doi. org/10.2307/1794477 This content downloaded from 134.58.253.56 on Sun, 12 Aug 2018 10:53:21 UTC All use subject to https://about.jstor.org/terms

36

SOILS AND SEDIMENTS

The large sediment load of the Indus has led to the formation of a large alluvial valley in the lower basin between the Thar Desert on the East and the Kirthar Range on the West spanning 150 The whole of the Indus Plain from the Himalayas to the Salt Range in the North to the Arabian Sea in he south has one of the most homogeneous physiographic regions of the Earthwith only the Kirana Hills in the upper part and the limestone ridges of Sukkur and Hyderabad to interrupt its flow of rivers. This makes its one of the most fertile regions in the area with fertile soil and abundant water supply (Memon, 1969).

Bordering both sides of its modern floodplain lie the >200-km-wide “historical floodplain” lands that have experienced prior changes in the location of the channel and meander belt. Thus, except far upstream, the Indus River flows through a 5 Ma alluvial landscape of its own making (Clift and Blusztajn, 2005; Giosan et al., 2012) (Syvitski & Robert Brakenridge, 2013).

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Soil Map of Sind 1978 Published by Direction of Dt. M. Bashir Choudhri. Director General. Soil Survey of Pakistan. https://esdac.jrc.ec.europa.eu/ESDB_Archive/EuDASM/Asia/lists/s2_cpk. htm

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02 ENGINEERED INDUS DAMS/BARRAGES/CANALS

The water of the Indus River has been used since the Ancient Indus Valley civilization for six millennia in an organized fashion. Beginning during British colonial era, the water management was made into a large scale management system. Currently 60% of the water if the Indus is used for irrigation for approximately about 80% of the agricultural fields in Pakistan(Inam et al., 2008). More than 150,000 km2 of 168,00km farmland is irrigated making it the largest irrigation to rain-fed land ratio (4:1)(Inam et al., 2008). A fine-grain mesh of canals and ditches was complemented by bunds which are 6-8 km from the main river trajectory. The bunds protect roads, railways, settlements and crops. As with all deltas, the expanse of the Indus Delta is shrinking, as upstream hydro-electric dams are built for energy and barrages are built to divert water for irrigation.

40

The agriculture industry of Pakistan is entirely dependent on the Indus and its tributaries, the Jhelum, Ravi, Chenab Sutlej and Beas Rivers. The waters of the Indus River and its tributaries are heavily utilised for irrigation in the relatively arid area and the river is a lifeline for the economy and culture of the region (Fahlbusch et al., 2004). Around 25 % of the modern drainage comprises irrigated crop land. The high population density of the Indus Basin (145 people per km2) results in major anthropogenic impacts. More than 90 % of the original forests within the drainage basin have now been lost.

Moreover, a number of dams and reservoirs in the basin have been constructed for flood control and electricity generation, which in turn have strikingly modified the channel and behaviour of the river(Inam et al., 2008)

https://ejatlas.org/conflict/tarbela-dam-pakistan

Three major water reservoirs on the upstream Indus, 19 barrages and headworks all along its length and 43 major canals provide water to farmlands. These structures have drawn water away from the Indus and diverted it to vast farmlands. The flow of fresh water down the Indus has dramatically decreased. The subsurface hydrology of the basin has also been affected and has also reduced the sediment flow of a river heavily laden with it. The annual sediment load of the pre-engineered Indus varied between 270 and 600 million t (Milliman et al., 1984). It is a fraction of that at present. Since most of the lower Indus Basin is flat, the natural drainage flow is gradually allowing the water table to rise. This with the vast canal system is leading to large scale problems of water logging and salinity. Now almost 60% of the aquifer underlying the Indus Basin Irrigation system is of marginal to brackish quality(Inam et al., 2008).

http://iamproudtobeasindhi.blogspot.com/2014/10/history-of-sukkur-part-2. html

The construction of the Mangla Dam in 1967 and the Tarbela Dam in 1976 in northern Punjab caused a major decline in the water and sediment discharge downstream. The average annual discharge of water and sediment before and after the construction of the water management structure fell from 107 billion m3 to 193 million downstream of the Kotri Barrage.

When rainfall has been low these figures have further declined. There have been days with no flow below the Kotri Barrage and times when the water of the Indus have not reached the Arabian Sea. There has also been a current trend of low rainfall in the Indus Basin (Inam et al., 2008). As a consequence braiding and sand bars have become common in the river south of Kotri. Sediment passing down the system tends to be deposited in the section below Kotri rather than maintaining the growth of the delta.

43

ANTHROPOCENE INDUS DELTA

The Indus River in the delta after human interventions of the 19th century has been reduced to a single channel.

The water network of the Indus delta is a complex system of natural branches, creeks, and artificial (mostly irrigation) canals. The delta contains many floodplain marshes and lakes, including oxbows, as well as seashore mangrove swamps(Kravtsova et al., 2009).

The apex of the delta unchanged during historic times was considered to be north of Hyderabad, where the river split into two branches. The west-ward branch was later converted into the Fuleli canal. It is suggested by (Kravtsova et al., 2009) that the present delta only be calculated according to its “active area” which is an area of tidal creeks as little as 6000km2. The abandoned delta however is considered to start near the city of Thatta and is calculated to be ~30 thousand km 2. The length of the delta coastline is 299km(Kravtsova et al., 2009).

https://www.thenational.ae/world/asia/india-accused-of-waging-waterwar-1.556900

https://www.thenational.ae/world/could-india-and-pakistan-be-about-to-enter-into-a-water-war-1.203152

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WATER AND SEDIMENTS FLOW

Sukkur Barrage during no flow days. https://sandrp.files.wordpress.com/2017/02/6.jpg?w=546

Kravtsova, V. I., Mikhailov, V. N., & Efremova, N. A. (2009). Variations of the hydrological regime, morphological structure, and landscapes of the Indus River delta (Pakistan) under the effect of large-scale water management measures. Water Resources, 36(4), 365–379. https://doi.org/10.1134/ S0097807809040010

The modern delta does not receive much fluvial water or sediment. Historically, its average coastal discharge was ~3000 m3/s; with diversions and agricultural use which has fallen to 300 to 800 m3 /s with long periods of no flow (Asif et al., 2007) in (Syvitski & Robert Brakenridge, 2013). There were no zero-flow days before the construction of the Kotri Barrage in 1955. No flow days are now upto 250 per year The average annual water and sediment discharges during 1931-1954 were 107km3 and 193 Mt, respectively. During 1993-2003 period these rates dropped to 10 km3 and 13Mt(Inam et al., 2008). The sea intrudes now upto 225 km upstream.

The delta thus changed from a fluvially-dominated delta system to a more tidally controlled system, with reworking of the abandoned delta channels.

The remaining portion of the delta is now a relict landform(J. P. M. Syvitski et al., 2013).

The drastic reduction of the water and discharge down the Indus following the construction of Kotri Barrage in 1955 resulted in the loss of several hundred square kilometres of fertile land. The once prosperous port area of Keti Bandar was reduced to a fishing village and the population was forced to change their age old profession of farming to fishing and also to migrate to other parts of the delta in search of fresh water and shelter from saline intrusions. The anthropogenic impact of upstream water and sediment blockage resulted in the shrinkage of the active delta and also stunted the growth of the mangrove forest(Inam et al., 2008).

Variation of water and sediment discharge below Kotri Barrage in Indus basin: (Inam et al., 2008)

Global warming is expected to dramatically affect the flow regime of the Upper Indus. According to many sources, the Indus basin climate change will result in increased availability of water in the short term and decreasing in the long run. Due to increased rate of glacial melt and increased flow, summer and spring discharges are expected to be reduced considerably from 2046-2065 with regards to the reference period of 2000-2007(Laghari et al., 2012). Reduced water availability will be felt most during the summer and spring months. Water from glacial melt will appear earlier than the main monsoon flows(Laghari et al., 2012)

45

DISTRIBUTING WATERS

https://farm9.static.flickr.com/8257/8641926689_71054aeaef_b.jpg

The Indus delta is a vast engineered landscape and its gradual slopes lend themselves to this way of distributing water very well. Any landforms in the alluvial plain which did hinder this distribution of water were obliterated by the this large-scale agricultural developments one of the largest irrigation networks in the world (Giosan et al., 2006). Eighty percent of Pakistan’s agriculture relies on the Indus River for water. Construction of barrages and connected canals for irrigations led to a systematic diversion oof water from the main channel of the Indus. The canals often follow old river courses.

In 1762, the earlist changes to the flow of the river were already being carried out in the Delta in the form of damming. Additional dams were built downstream until 1783 with a dam successfully closing the Eastern branch of the Indus. The modern system was developed in 1859 under British Rule When the Eastern Nara branch was changed from an overflow channel to a perennial branch (J. P. M. Syvitski et al., 2013).

The Indus of the Anthropocene limited by levees has become a manipulated hydrological system (J. P. M. Syvitski et al., 2013).

http://mw2.google.com/mw-panoramio/photos/medium/56058371.jpg

BUILT AREAS ROADS RAILWAYS BUNDS CANALS KOTRI BARRAGE-1955 CURRENT RIVER INDUS

0 0 0

46

5

10 5miles

20km 10miles

BUNDS

Women walk on a “bund” behind which lies the Indus River.

“Bunds” are engineered artificial levees. They constrain the meandering channel of the Indus River within the 7- 20km wide floodplain (Syvitski & Robert Brakenridge, 2013). In the delta they run parallel to the river almost to the mouth of the Indus.

Over deacdes there has been construction of artificial levees to protect agricultural lands from inundation during floods which started near Sukkur in 1869(Asianics Agro. Dev., 2000). By the time the Sukkur Barrage was constructed in 1932, the eastern bank of Indus included a complete line of bunds from the Sindh/ Punjab border continuing 1500 km all the way down the delta (J. P. M. Syvitski et al., 2013). With the completion of the Kotri Barrage in 1955, associated flood bunds constricted the active Indus River to a floodplain of only 7-15 km wide(Asianics Agro. Dev., 2000). The fluvio-deltaic system of the delta of the Indus was constrained to a single channel(J. Syvitski et al., 2009).

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https://tribune.com.pk/story/939203/transportation-through-indus-climate-ministry-objects-to-punjab-govts-initiative/

KACHA

OLD FLUVIAL PLAIN

BUND

RIVERINE AREA

The wide alluvial floodplain, commonly known as the riverine or kacha area, was bound by the Kirthar Mountains and the Thar Desert. Sediment and alluvial deposits were spread over a wide area making the valley extremely fertile. Anthropocene changes have seen this area decrease to a few kms as mentioned before by engineered bunds. Panhwar (2002) points out that the entire riverine area was the most prosperous in the prebarrage period, but was ruined in recent decades(Kazi, 2014). Of the riverine area, some 1800 km2 of the riverine tract is reserved by the government as the forestland, while 4,000 km2 is designated as the agricultural land, and the rest is covered by villages, graveyards, and uncultivable wasteland. The land on either side of the riverine area is considered fit for human settlements.

https://tribune.com.pk/story/915069/law-and-order-hideouts-tunnels-uncovered-in-dg-khan-operation/

49

VEGETATION IN THE DELTA

Dying mangroves in Indus Delta Photo: The Nation http://tns.thenews.com.pk/dying-indus-delta-and-fresh-water/#.W3RIWugza00

The riverine area.

Photo by Author.

Mangroves and riverine area vegetation is the only substantial natural vegetation in the delta, where there also used to be natural and irrigated forests. More than 90 % of the original forests within the drainage basin have now been lost. The mangrove ecosystem of the Indus Delta is perhaps unique in being the largest area of arid climate mangroves in the world (IUCN, 2003). Howver mangroves have decreased to as much as 85% in the active delta. The mangrove system has also been degraded. The population living around the coastal mangroves depend on them for their livelihoods.

Atleast three-quarters of the rural population of the delta depend, directly or indirectly, on fishing as their main source of income, and most of Pakistan’s commercial marine fishery operates in and around the mangrove creeks on the coast of Sindh Province. A large proportion of fish and crustaceans spend at least part of their life cycle in the mangroves, or depend on food webs originating there (Meynell and Qureshi, 1993).

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The major changes in river flow below Kotri (the last headwork before the river water flows to the sea) have affected the ecology in lower Sindh and the coastal areas.

The majority of the Indus plain is occupied by vast tracts of irrigated land for local and consumption and export.

Agriculture in the delta occurs in two cycle called Rabi (wet season) and Kharif (dry season) as in the rest of the Indus Basin. The suitability of the delta for some crops has been decreasing due to an increase in salinity.

Of the irrigated area (228 694km2, 21% of basin area) of the Indus Basin about 60.9% is located in Pakistan, 37.2% in India, 1.9% in Afghanistan and 0% in China.

The Indus Basin Irrigation System (IBIS) is the largest irrigation system in the world (Laghari et al., 2012).

http://tns.thenews.com.pk/wp-content/uploads/2016/01/Naseer-memon.jpg

Irrigation efficiencies in the Indus Basin Irrigation System are low. Much of the surface water that enters the system is wasted (also to groundwater recharge) through evaporation and seepage though canals. This is responsible for the continuous shortage of irrigation water in Pakistan and especially in tailenders such as the Sindh province. Pakistan is close to using all its available water resources in most years in the current situation (Laghari et al., 2012).

DRAINAGE STRUCTURES LEFT BANK OUTFALL DRAIN

858

Drainage systems such as the Left Bank Outfall Drain have been constructed in the basin but due to the rather flat terrain of the delta have been less effective and have led to the intrusion of sea water to about 80km upstream(Panhwar, 1999). A number of man-made seepage channels totalling 837 were constructed to collect the seepage water and drain it into the 160 km main spinal drain as part of the Left Bank Outfall Drain project (LBOD),which covered the regions, falling within the command areas of the Sukkur and Kotri barrages, consisting of the areas in Nawabshah, Mirpurkhas, and Sanghar. Together, these manmade seepage channels were designed to drain 5million, acre of land, which constitute 38 % of the 13million acre fit for human settlements.

Nat Hazards (2014) 70:839–864

The remaining 62 % of the area is without any drainage facility(Kazi, 2014).The LBOD was later extended to include the Tidal Link which drained the water into the Arabian Sea. This proved to be problematic and led to the worsening of floods in the districts of Sindh in 2010(Kazi, 2014).

The construction of LBOD was blamed for altering the natural flow pattern, generally from the north to south, in the area. Nevertheless, the project benefited farmers in Nawabshah, Sanghar, and Mirpurkhas Districts, and brought some 1.25 million acres of waterlogged land, is back into cultivation(Kazi, 2014).

Kazi, A. (2014). A review of the assessment and mitigation of floods in Sindh, Fig. 13 Left Natural bank outfall main drain (LBOD), including https://doi.org/10.1007/s11069Spinal Drain, Khadhan Pateji Outfall Drain Pakistan.

Hazards, 70(1), 839–864.

(KPOD), Dhoro Puran Outfall Drain (DPOD), and Tidal Link (adapted from Asian Development Bank 2000) 013-0850-4

123 52

DHORAS

Nat Hazards (2014) 70:839–864

Nat Hazards (2014) 70:839–864

847

847

In the times of floods, the river overflows the bunds and flows through natural inundation low-lying areas called dhoras, The flow of water through these dhoras are now totally or partially blocked by human settlements, and infrastructure. Dhoras in Sindh have been identified on the left(east )bank of the river by a team of consultants for the Sindh Irrigation and Drainage Authority though the Louis Berger Group and Indus Associated Consultants (Kazi, 2014).

Kazi, A. (2014). A review of the assessment and mitigation of floods in Sindh, Pakistan. Natural Hazards, 70(1), 839–864. https://doi.org/10.1007/s11069013-0850-4 Fig.55 Major MajorDhoras, Dhoras, identified bank of river Indus adapted and Indus Fig. identified on on thethe leftleft bank of river Indus adapted from from LouisLouis BergerBerger GroupGroup and Indus AssociatedConsultants Consultants (2012) Associated (2012)

53

NATURAL + ENGINEERED FLOODS

Since 1947 there have been seventeen major floods including the one in 2010. The climate change (Farooqi et al. 2005; Memon 2008), including seasonal variations in temperature, wind direction, intensity, and distribution of rainfall, as well as the timing of glacial melt and outbursts of glacial lakes are important factors controlling the onslaught of floods (Kazi, 2014). Also its geomorphic character with a high sediment load, typical for many Himalayan rivers, adds to the extent of the catastrophe and the unpredictability of the river(Laghari et al., 2012).

Flood control strategies on Himalayan rivers are till today primarily embankment based. Therefore the river has been accumulating sediment and aggrading rapidly during the last decades, making it a “superelevated river” in several reaches, which is considered to be prone to avulsion. Deforestation in the basin has led to increased erosion and sedimentation (Da Silva and Koma, 2011; Ali et al., 2005), as well as faster flood runoffs. The draining of natural wetlands has increased flooding. The wetlands that once surrounded the Indus River tamed floods, by regularly taking up parts of flood waters during monsoonal seasons and slowly releasing them again (Laghari et al., 2012) Change in flow regimes due to low flows in eastern rivers after the Indus Water Treaty and enhanced flood protection measures have attracted economic activities and settlements in the floodplains, 54

Stagnant water surrounding settlements remaining fro months after the 2010 floods. https://earthobservatory.nasa.gov/Features/PakistanFloods/page3.php (Photograph courtesy Defense Video & Imagery Distribution System.)

Flooded agriculture fields in Sindh, 2010 http://www.ibexmag.com/pakistan-economy/economy-articles/recent-floodgoing-cause-sizable-dent-bourse/

in a country with an increasing population and substantial poverty. Vulnerability on such locations has increased due to a false sense of safety.

The river Indus in Sindh flows at a higher elevation as compared to its floodplain. This makes the river in Sindh particularly hazardous from a flood point of view.

The only way for water to be dissipated after flooding is to be pumped back to the river or dry up through evaporation. In the meantime, while the land is flooded with water it cannot be cultivated. Due to increased settlements and constructions in the floodplains, water that enters the inundation zone has its drainage path back to the main river interrupted by levees, roads, railway lines and canal embankments. The result is that water does not drain back. The relationship between anthropogenic environmental degradation and catastrophic flooding is well documented (Mustafa and Wrathall, 2011). Conversely, we know there is an established link between healthy watersheds with flow capacity – wetlands, marshes, estuaries and mangroves – and flood mitigation. This disaster has stressed the urgent need to move from “river control” to “river management” strategies (Laghari et al., 2012).

Flood Stages in Sindh with respect to Guddu Barrage.

Discharge * is equal to 100,000 cusecs is equal to 100,000 cusecs; and 01 cusec is equal to 01 cubic foot per second

Super Floods in Sindh with repect to the Guddu Barrage.

(Kazi, 2014)

INDUS AVULSIONS-FLOODS 2010

snowmelt-driven hydrometeorology and by continuing uplift of the Himalayan orogen, forming its highest topography to the north, and by sediment compaction and subsidence downstream and in the delta.

Some aspects of the 2010 monsoonal rains were unusual (Houze et al., 2011). July– August precipitation totals were above average but not exceptional for Pakistan as a whole (Precipitation; see GSA Supplemental Data [footnote 1]). However, northern Pakistan rainfall rates during monsoon storms were extreme compared to 1998–2010, and there were unusually frequent downpours (Webster et al., 2011). The Supreme Court Inquiry

It is noteworthy that the monsoon of August 2010 brought with it the worst riverine flood after a period of 80 years, affecting Khyber Pakhtunkhwa, lower Punjab, Baluchistan, and Sindh regions(Kazi, 2014).

Although excessive rainfall has been cited as the major causative factor for this disaster (Houze et al., 2011; Tariq and van de Giesen, 2011), the human interventions in the river system over the years turned this disaster into a catastrophe (Gaurav et al., 2011).

The Punjab, Gilgit Baltistan, and Azad Kashmir provinces that commonly receive monsoon deluges include stations with July 2010 rainfall totals of >500 mm. Pakistan- wide August rainfall totals were 75% of July totals. The flood wave then moved downstream into drier areas during the months-long catastrophe: Sindh Province suffered the worst of the flooding but received relatively little rainfall throughout the monsoon. The downstream regions had weeks of advance notice of the expected high Indus discharges, yet exceptionally high damage still occurred (Syvitski & Robert Brakenridge, 2013).

C 27 ea w su al ge p. fa u fo T K m 20 w Ju d m su re th h ex ex

it si in p ca es th F la tw re co T es o o 31 st m 32 31 w at at fo 20 is

The delta avulsion which occurred in this location in recent and ancient history, breached the bunds, natural and engineered in high floods. In the times of floods, the river overtops the bunds and flows through natural inundation low-lying areas called dhoras, The flow of water through these dhoras are now totally or partially blocked by human settlements, and infrastructure.

Avulsions on the River Indus in 2010 floods Figure 1. Summary map showing the progress of the 2010 Indus flood wave and its two main avulsions, (Syvitski & Robert Brakenridge, 2013)

key features, and towns. Arrows show the direction of overbank floodwater as determined by progressive inundation from the remote sensing data (see Flood Inundation and Chronology, GSA Supplemental Data [text footnote 1]). Day 222 is 10 August 2010. See Figure 3 for data on profiles CS1, CS5, CS8, and CS9.5.55

th at D A G

!

The Delta Avulsion which has occurred in this location in recent and ancient history, breached the bunds in high floods to flow through the delta flooding the town of Sujawal and smaller settlements and agriculture in its way. Approximately 10,000 m3 /s of water was discharged into this avulsion. The delta avulsion in 4 days had advanced 45 km flooding the town of Sujawal. This however also prevented other more populated areas from being flooded (Syvitski & Robert Brakenridge, 2013).

56

A flooded riverine area in August 2010and a river avulsion visible on the South East of the River.

!

The riverine flood subsides by Sept 2010 but the avulsion water remains, inundating a major area of the delta, flooding settlements and agricultural land, unable to drain into the Arabian Sea

57

The breach in the bund can be seen with river in high flood. People seek shelter on top of the bunds while the city of Sujawal, which lay in the path of the avulsion was flooded as seen in the aerial image. Water filled the streets and the homes in the settlements.

As the bund is breached the flow of water through the avulsion is less than 0.4m/s while in the Indus the flood water is flowing at speeds greater than 2m/s.

Redrawn from (Syvitski & Robert Brakenridge, 2013) SECTION AA

INDUS 2010 FLOOD

DELTA AVULSION SLOW

FAST 10,000 m

58

20,000 m

AA

The map showing the breach of the bund on the left bank of the river that caused the delta avulsion in 2010. The floods reached the parallel bunds that limited its flood plain and at a weak point it breached a bund to flow in a direction dictated by the topography and gravity. The avulsion flow was towards the south-east, flooding the large city of Sujawal on its way down towards sea. Large areas of agricultural land and small settlements and villages were inundated. Inadequate drainage and hinderances such as infrastructure(roads/railways and canals) caused the water to remain stagnant for months before evaporating.

59

REINSCRIBING THE NATURAL DHORA PREPARING THE LANDSCAPE

The 2010 flood indicate a path the river took that is a natural drainage of the river had it not been confined to its narrow “kacha” plain. The delta avulsion naturally occurs on a route that the river has taken in historic times. Being a natural geomorphological process the delta avulsion has been cause by decades of scouring of the land and is one of the natural drainage paths of the delta. This site of drainage is inscribed in the larger system of natural and engineered drainage of the lower province of Sindh and the Delta. It forms a “dhora”( a naturally low lying area of drainage) in a system that drains the delta in times of flood.

The existing drainage routes link to the large “dhunds” (brackish lagoons) with associated marshes and mudflats that lie near the Rann of Katchh. The natural route of the Delta can link to the Nareri Lake and to creeks through which the water can drain to the Arabian Sea. This reinforces by making use of the natural rhythm of the landscape instead of going against it as a sytem of braided channels.

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THE BRAIDED DHORA

To optimise maximally the drainage route of the avulsion to the sea, the breaching of the bund will have to be more intentional and methodical according to the flow of the water in the river in different cycles. The Indus river is in flood every year during the monsoon and this can be used to let water through this delta dhora. In the heavy floods every four to five years will also allow more water to pass through the avulsion and create a more frequent passage for the water. In the avulsion that was caused by the 2010 floods, the water was not able to flow to the lagoon through its route fast enough and was left stagnant because of infrastructure such as roads and canals. These infrastructures should adapt to being far more porous and allowing free passage of water. The surface of the avulsion then needs to be reworked for optimum drainage to create gradients that facilitate this flow of water. The avulsion can take the form of a braided system with channels that connect and drain out low lying areas where water accumulates.

62

INDUS IN SUPER FLOOD

In the case of a heavy flooding on the Indus, the avulsion will also be able to allow for high levels of water. Some parts of the larger urban islands will be completely protected against the water and will remain dry and accessible.

All infrastructure is raised to accommodate this flow of water. Roads will become viaducts which allow unhindered flow. The canals will be integrated with the flow direction of the braids to allow maximum drainage of the water. The braids and canals become interchangeable water carriers.

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The buildings in flood prone areas should be erected on elevated spots. Ideally, the floodplain areas should be free from any development, so that the impending flood could accommodate flows with minimal risk. To allow for this unhindered passage of water, elevated spots are made according to the existing settlements and the pattern that the water took in the avulsion according to the topography and the direction of flow of the water. Any settlements which are in areas that are in the path of the water will be relocated to more suitable areas as concentrated urban settlements grouped together. These islands with the settlements will be sites for new development.

WATER FLOODED WATER ISLAND FLOODED URBAN URBAN ISLAND BUND WATER BUND FLOODED WATER ISLAND FLOODED URBAN URBANISLAND ISLAND URBAN BUND URBAN BUND ISLAND POND POND ISLAND URBAN WETLAND GREEN URBAN ISLAND WETLAND GREEN AGRICULTURE LEVEL 01 POND AGRICULTURE LEVEL 01 POND AGRICULTURE LEVEL 02 WETLAND GREEN AGRICULTURE LEVEL 02 WETLAND GREEN WET FOREST LEVEL 01 AGRICULTURE WET FOREST LEVEL 01 AGRICULTURE ISLAND FOREST AGRICULTURE LEVEL 02 ISLAND FOREST AGRICULTURE LEVEL 02 WET FOREST WET FOREST ISLAND FOREST ISLAND FOREST

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VEGETATION IN THE DHORA

The vegetation in the delta including mangroves, riverine forests have been considerably lost. A vast re-vegetation drive needs to take place depending on the different levels of the ground which has grown quite high in salinity. The growing vegetation also will help with consolidation of the ground and in combating increasing aridity.

The lowest level of the micro topography which will be ponds with wet vegetation. Intermediate levels will have agriculture based on ground distance to water, with wet and dry agriculture. The driest form of agriculture will be on the top of the protected level of the islands.

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Around the islands will be an area which can be flooded in the event of high floods. This area will host wet forests with clearings for urban settlements.

These settlements will have to adapt to a varying flood regime with wet and dry periods and the typology of these settlements will have to be accordingly built.

The highest levels of the island will have forests that are dispersed throughout the settlement. They will take advantage of all empty space in the urban areas.

This forest can change with the change in the urban environment.

SUJAWAL SUJAWAL

Sujawal city is the main city in the Sujawal district of Sindh. It’s a historical city which now has a population of around 800,000. The city is said to have been famous for its wetlands. This seems to be evident in the agricultural plot divisions in the area around Sujawal which are take on fluid forms. Many canals crisscross through the area around the city and even through it. It also sits just a little distance from the main river and its 10 foot high levee.

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Sujawal city is the main city in the Sujawal district of Sindh. It’s a historical city which now has a population of around 800,000. The city is said to have been famous for its wetlands. This seems to be evident in the agricultural plot divisions in the area around Sujawal which are take on fluid forms. Many canals crisscross through the area around the city and even through it. It also sits just a little distance from the main river and its 10 foot high levee.

THE FLOODEDFLOODED CITY SUJAWAL-THE CITY

In 2010 with the floods a breach occurred in the southeast bank of the Indus. It occurred in a place which has previously experienced similar changes through recent history and pre-history (Holmes, 1968; Wilhelmy, 1969).

This completely flooded the city of Sujawal and resulted in the residents seeking refuge on the nearby levee. This though lessened the severity of the floods in areas further south (J. P. M. Syvitski & Robert Brakenridge, 2013).

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In 2010 with the floods a breach occurred in the southeast bank of the Indus. It occurred in a place which has previously experienced similar changes through recent history and pre-history (Holmes, 1968; Wilhelmy, 1969). This completely flooded the city of Sujawal and resulted in the residents seeking refuge on the nearby levee. This though lessened the severity of the floods in areas further south(J. P. M. Syvitski & Robert Brakenridge, 2013).

SUJAWAL-THE ISLAND THE ISLAND

An existing road which was built after the 2010 floods An existing waslevee builtwhich after protects the 2010the floods can be maderoad intowhich a strong can from be made into a strong levee protects the city the direction in which the which water comes city from the direction in which theinwater comes down through the avulsion mainly the north anddown through the avulsion mainly in the north and the the west. The city should also be raised to protect west. it The cityfloods. shouldThe alsoroads be raised protectand it insewage high floods. in high and to drainage The roads andalso drainage sewage also infrastructure needsand to be raisedinfrastructure to not be needs to be raised to not be damaged in the avulsion damaged in the avulsion and also allow water an and also allow unhindered path water to flow.an unhindered path to flow.

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The city would then have a hard engineered side The city would have water a hardand engineered side which which faces thethen incoming the opposite soft faceswhich the incoming andsurrounding the opposite soft inside side can blendwater with the terrain which canof blend with the surrounding terrainlevee in the the form terraces or slopes.

The engineered form of terraces or slopes.

The engineered levee will protect the most vulnerable spot of the island will protect most vulnerable spotofofwater the island from itthe from thethe immediate heavy flow and divert immediate heavy flow of water and divert it around around the island as a braided river that drains it outthe island as a braided river that drains it out eventually. eventually.

Urban growth then can take place on either the Urban growth take onsofter eithersloping the highest highest parts ofthen the can island orplace on the side, parts ofis the island or from on the softer sloping side, whichofis which facing away the water.

The typologies facingtypes awayof from the water.would The typologies of both types both settlements be according to their of settlements would be according to their location. location. On the top the way of building can be as is On the top the way of building as ismore the custom to build the custom to build in thecan areabewith of higher in the area with more of higher density and less sprawl. density and less sprawl.

In the sloping area that face away from directly In the sloping area that face away from directly incoming incoming water, the presence of water is a possibility water, presence of water is a slopes possibility in high in high the floods.

Settlements on these should floods.

Settlements on these slopes should be be raised off the ground to allow for water and raised off the ground to allow for water and settlements settlements to exist simultaneously.

All other “islands”to exist the avulsion in thesimultaneously. avulsion follow All theother same“islands” logic, theinsystematic follow the same logic, the systematic application application of which would make an archipelago in theof which would make an archipelago in the avulsion. avulsion.

WATER FLOODED URBAN ISLAND BUND WATER FLOODED URBAN ISLAND URBAN ISLAND BUND POND URBAN ISLAND WETLAND GREEN AGRICULTURE LEVEL 01 POND AGRICULTURE LEVEL 02 WETLAND GREEN WET FOREST LEVEL 01 AGRICULTURE ISLAND FORESTLEVEL 02 AGRICULTURE WET FOREST ISLAND FOREST

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THE ISLAND INISLAND AVULSIONS SUJAWAL-THE IN AVULSIONS

In the floods, the avulsion will flood theevent eventof super of super floods, the “dhora” will be completely, leaving urban areas and areas transport completely inundated, leaving urban and transport links safe safe on from inundation. in apart the from higher ground. Everything All low lyingelse areas surrounding expected to This be flooded in itthe highest the island willis be flooded. water as flows will be flood. drained out through the braided channels which will guide This as it Lake flowsand willeventually be drainedtoout the it to water the Nareri thethrough Arabian Sea. braided channels

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“DHORA” VEGETATION SUJAWAL-NEW VEGETATION

The vegetation in and around the island is dependent The vegetation in and around the island is on the levels of the terrain like in the rest of the dependent on the levels of the terrain like in the avulsion. There are existing raised platforms in between rest of the avulsion.

Thereare arelinked existing agricultural fields which to raised levees which platforms in between agricultural fields separate the fields and the keep water in thewhich fields. are These linked to levees which separate the fields and the raised platforms and linked pathways can be used for keep water in the fields.

These raised platforms cultivation.

Planting of trees consolidate the platforms. and pathways for cultivation.

The linked agriculture on topcan of be theused platform will be suitable for drier ofconditions and safethefrom incoming Planting trees consolidate platforms.

Thewater. agriculture on top of the platform will be suitable for drier conditions and safe from incoming water.

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There’s an intermediate level of agriculture that can There’s an intermediate level of agriculture that can be more wet agriculture in the monsoon months. be more wet agriculture in the monsoon months.

All agriculture needs to be suitable for saline All agriculture needs to be suitable methods for salineneed to conditions of the delta.

Cultivation conditions of the delta.

Cultivation methods need be switched to saline . The lowest points of the micro to be switched to saline .

The lowest points of the topography will be brackish ponds for fish farming. micro topography will bebebrackish ponds fish Surrounding it would swamps andformarshes. farming. Surrounding it would be swamps and marshes.

Sujawal used to be known for its marshes and as the Sujawal used to be known for its marshes and as patterns of the agricultural fields indicates; the soil the patterns of the agricultural fields indicates; might still have the potential to change to a more wet the soil might have the potentialhelps to change ecology.

The still increased vegetation deal with to a more wet ecology.

The increased the growing aridity of the region. The vegetation diverse ecology helps dealcreate with the growing aridity the region. will help a neo-natural systemofwhich builds on The ecologystructures. will help create neo-bring down the diverse old landscape It will ahelp natural which buildsa onmore the old landscape growingsystem salinity, support diverse habitat. structures. It will help bring down growing salinity, support a more diverse habitat.

FRAMES FOR URBAN DEVELOPMENT

The The settlement settlement pattern patternon onthe thesofter softerside sideofofthe theisland will follow the slopes of the topography, in the form island will follow the slopes of the topography, in of mini terraces and are more dispersed.

They the form of mini terraces and are more dispersed.can be with elevated platforms so they do Theyconnected can be connected with elevated platforms not become inaccessible during floods.

The typology so they do not become inaccessible during floods. of the houses follows these slopes to allow water The typology of the houses follows these slopes to to flow beneath with out harming the settlement.

allow water to flow beneath with out harming the settlement.

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The forest forest surrounding surrounding this The thissettlement settlementisisaawet wetforest which will consolidate the slopes forming clearings forest which will consolidate the slopes forming for settlements. the water fills in the braids clearings forAssettlements.

Asupthe water fillsits upallowed in to flood one side and to be completely blocked the braids its allowed to flood one side and to befrom the other side by a dike. levels of the completely blocked fromDifferent the other sideon bytop a dike. new islands in the archipelago can host various kinds of Different levels on top of the new islands in the agriculture which is different in soil and water conditions archipelago can host various kinds of agriculture of agriculture in the lower parts of the avulsion. which is different in soil and water conditions of agriculture in the lower parts of the avulsion.

Thesettlement settlement patterns patterns on The on the the top topof ofthe theisland islandare integrated with the forestation.

The forestation becomes a are integrated with the forestation. The forestation frames further development.

This also limits the urban becomes a frames further development.

This also spread away from infrastructures such as the road. The limits the urban spread away from infrastructures irrigation methods respond to salinity in the land and such as the road. The irrigation methods respond use planting techniques such as rows of certain species toofsalinity in the land and use planting techniques trees that help combat water-logging and salinity. such as rows of certain species of trees that help combat water-logging and salinity.

Areas near willwill be floodable if there an excess Areas nearthe thebraids braids be floodable ifisthere is of water in the avulsion.

The dike/road becomes the big an excess of water in the avulsion. The dike/roadinfrastructure the which protect the urban areawill from flooding. becomes bigwill infrastructure which protect the urban area from flooding.

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CONCLUSION

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The intentional flooding of the scoured path of the avulsion gives the area in the delta a new environment. This environment tries to become as natural as possible using landscape itself as infrastructure which have existed for thousands of years and will continue to influence the lives of the people living in the delta.

It will allow living in the delta and with a river, existing simultaneously in harmony with each other reaping mutual benefits and growing more sustainable.

The delta as it is vulnerable at the moment needs to fall back to more hybrid solutions that work with the forces of nature and its rhythms which are now lost but never completely erased from the landscapes.

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