Water symbiosis in the desert by Michela Musto

W a t e r i n

Michaela Musto

S y m b i o s i s t h e

Zohra Yasmina Rougab

d e s e r t

Carlos Zulueta

Architectural Association School of Architecture Emergent technologies and design 2012-2013 3

Master of Science Dissertation Programme: Term: Condidates: Thesis title: Submission: Tutors:

Emergent Technologies and design 2012 - 2013

Michaela Musto, Yasmina Zohra Rougab, Carlos Zulueta

Urban Symbiosis in the Desert 20/09/2013

Michael Weinstock, Programme Director; George Jeronimidis, Programme Director; Evan Greenberg, Studio Master; Mehran Ghaleghi, Studio Tutor; Wolf Mangelsdorf, Visiting Professor

Architectural Association School of Architecture Graduate school Programme

Programme: Term: Student name: Thesis title: Submission date: Course tutor:

Emergent Technologies and design 2012 - 2013 Michaela Musto, Yasmina Zohra Rougab, Carlos Zulueta Urban Symbiosis in the Desert 20/09/2013 Michael Weinstock

Declaration: ‘‘I certify that this work is entirely my/our own and that any quotation or paraphrase from the published or unnpublished work of others is duly aknowleged.’’

Signature of students Michaela Musto

Yasmina Zohra Rougab

Carlos Zulueta

A c k n o w l e d g m e n t s

Contents Domain 17 Methodology 45 Experiments 67 Design Proposal 111 Evaluation & Conclusion 113 Critical Essays 115 Bibliography 117

A b s t r a c t

I n t r o d u c t i o n

INTRODUCTION

1.1 World map showing the population distribution and growth

2. Clim ate c h a n ge a n d des e r t if icat io n Every year 12 million ha of land are lost to desertification, and the rate is increasing. Desertification is a major environmental problem that is advancing at an alarming pace.

1 . U r b an izat i on a n d d em o g ra p h i c exp a n s i o n

2. C lim ate change and des e rtif icatio n

In the recent years, the world has seen a rapid economic expansion. This has markedly affected the urban population growth. Thus, it is argued that, cities are places where economy, industry and wealth prosper the most. Therefore, people tend to move closer to the urban areas so they can improve their standards of living. For instance, The World Health Organization asserts that, major world population is currently living in cities, compared with hundred years ago when only 2 out of 10 individuals lived in the city. This pace has continuously soared along the years and is expected to reach 7 inhabitants out of 10 by 2050. Parallel to that, projections lately made by the United Nations suggest that global population growth might drastically increase by 2050 to reach 8.9 billion and could even hit the 10.6 billion inhabitants.

Examples of most dense cities today such as, Dhaka in Bangladesh and Mumbai in India, or a more developed world as Hong Kong are alarming situations that must be considered while designing future cities for next generations and less harmful for the planet. In addition, the city’s’ gas emissions and fossil fuel use are real threat for the earth, causing climate change that also enhance the advance of deserts and thus, threaten the mankind and all living species to last.

It is widely believed that moving to the city can improve peoples’ standards of living. However, it is also argued that it could be detrimental when massive communities gather in poor areas and become exposed to pollution and disease due to the luck of urban infrastructure to manage the city waste and sewage. Similar to that happened in London 150 years ago, or recently in many third world cities, where urban infrastructure are not effective to maintain the healthy lifestyle for citizens.

10.6

POPULATION (billions)

Architects and urban planners should not disregard these facts but rather find alternatives and learn from ancient and present model of the city as Lewis Mumford (1966) said: “If we would lay a new foundation for urban life, we must understand the historic nature of the city.” To summarise, more people are predicted to inhabit the city; Deserts in the other hand will remain empty. Covering almost one third of the earths’ land surface area, Deserts if attentively approached could be crucial loopholes for the mankind to subsist. However, living but also erecting cities in Desert land can be a challenging task. The absence of water and the lack of vegetation are critical to their development and their characteristic morphology.

ADVANCING DESERTIFICATION

POPULATION GROWTH

0,000 736 %

0,000 752 %

0,000 768 %

0,000 784 %

0,000 8 %

0,000 064 %

0,000 048 %

0,000 032 %

0,000 016 %

2 1950

1960

1970

1980

1990

2000

1. Cotation

2010

2020

2030

2040

2050

0 1950

0,00077%

1960

1970

+ 78 000 000 people every year

1980

1990

2000

2010

2020

2030

2040

2050

+ 48, 28 km per year

ONE THIRD OF THE EARTH’S SURFACE ARE DESERTS

Introduction

Chapter One

Domain

ARID CLIMATES

IN T RO DUC T IO N

Desert lands cover more than one third of the earth surface. According to the Koppen- Geiger classification these desert are divided into various climates depending on the degree of aridity and temperature variations.

H OT S E MI- AR ID ZONES 1.2 Hot semi-arid zones

Generally located in the tropics and subtropics. They have a hot, sometimes extremely hot, summers and mild to warm winters. Snow rarely falls in these regions.

CO LD S E MI- AR ID ZONES Located in temperate zones. They are typically found in continental interiors some distance from large bodies of water. Hot and dry summers though they are typically not quite as hot as those of hot semiarid climates. Cold winters with some snowfall. They usually have more altitude than hot semi-arid zones. 1.3 Cold semi-arid zones

H OT AR ID ZO NES Found under the subtropical ridge where there is largely unbroken sunshine for the whole year due to the stable descending air and high pressure Temperatures varies between 40â °C to 45â °C.

1.4 Hot arid zones

COL D A ND M I L D A R I D ZO NES Typically found in temperate zones, almost always in the rain shadow of high mountains which restrict precipitation from the westerly winds. Mild arid climates are usually found along the west coasts of continents at tropical or near tropical locations, or at high altitudes. Atacama desert is part of this classification and is considered to be the driest in the world.

Atacama desert

62 5 12

rati on

rati spi

an otr

ap nti a

l ev

(m 00

3 °C

Pot e

on 1.5 °C

4 00

6 °C

Cool desert

24 °C

Subtropical Tropical

12 °C

80 00

Warm temperate

Cool temperate

ati ipit

rec

Subpolar Boreal

Polar

Atacama desert is located in the northern coast of Chile. It is classified as a cool desert with a temperature not exceeding 25 degrees. It is known as the driest desert in the world with less than 60 mm a year and high evaporation (55.3 mm/year), almost equal to the precipitation amount per year due to high solar radiation. This desert represent a genuine challenge to address the issue of inhabiting the desert. As most of the arid climates, water remains the main issue to confront.

Latitudinal regions

0.5

ATACA M A D ES E RT

al p

0.2

0.1

1.4 Cold and mild arid zones

Hyperarid

Perarid

Arid

Semiarid

Subhumid

Humidity provinces

Humid

Perhumid

Superhumid

Critical temperature line

1.5 Climatic domain

WATER WAT ER AND C IV ILISAT IO N

1.6 Netherland...

Water is a vital element to all living forms. It has markedly shaped human civilisation since ancient times. Small settlements started to emerge next to water bodies to ensure their basic needs of water and food. Overtime, mankind developed ways of bringing water instead of moving to it. Innovative techniques were employed to collect, transport and store water through the force of gravity, such as Aqueducts and Qanats systems …etc. This has brilliantly affected the development and the prosperity of civilisations. 1.6 Water organizing the city

WO R LD ’S WAT ER S H O RTAGE The United Nations World Water Development Report (WWDR), assert that The world’s population growth is about 80 million people a year, implying increased demand of fresh water by about 64 billion m³ a year.

Fresh water

2.5 %

Breakdown to fresh water resources

Saltwater

97.5 %

30 % Groundwaters

Around 75% of the earth’s surface is covered with water, 2.5 % of it is considered to be fresh water, but only 30% of this amount is accessible to the human use such as ground waters, lakes, aquifers, and rivers. However, this amount of water is not equally distributed on the earth surface. Moreover, some dry deserts do not receive sufficient rainfall for the recharges. For instance, Atacama Desert in the coastline of Chile is considered to be the driest desert in the world.

Available

70 %

Ice & snow cover in mountainous regions

Unvailable

0.3 %

Fresh water_ Lakes & rivers

1.7 diagram showing the amount of fresh water available for human use.

1.7 World water availability

1.7

B IOM IM E TI C Mimicking nature could be the answer for many issues we humans may face. Many systems has been extracted in order to cope

BIOLOGICAL SYSTEMS: TAMARUGO 1. FAO, 2003, The Current State of Knowledge on Prosopis tamarugo

1.1 Diagram showing how the tree captures the water and then it stores it in the soil to avoid evaporation. 1.1 Graph showing how the stomatal opening increase during night

1.1 H. Larrain, moist air 2009, http://ecoantropologia.blogspot. co.uk/2009_01_01_ archive.html

C H A R AC TE R I ST IC S Tamarugo is an endemic specie from the desert of Atacama which has a high tolerance to salted soil. It has small leaves It's considered a drought tolerance specie, meaning that is capable of sustain a long period without water and even go into a dormancy period.

S U RV I V I NG ST R AT EGY Some parts of Atacama desert haven't record rain since it started to be recorded. In this harsh environment the leaves of this specie are capable of collecting water from the air moisture during night, where the relative humidity increase considerably. Afterwards, the moisture is driven gradually to the roots where since they are under the soil and at a drythe air air, the evaporation lower temperature than and transpiration ratio is lower1.

STO M ATA L O P ENIN G While the transpiration ratio of this tree is of 256

moisture mm/year for a 100 trees plantation, the stomata storage in differently than most of trees when closing the works soil

1.1 Humidity 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% 12:00 16:00 20:00 24:00

4:00

8:00

12:00 16:00

% stomatal opening Junoy

during night to avoid water loss, and opening during night in order to maximize the water capture from the air when there is sufficient.

% stomatal opening Canchones % relative humidity Junoy % relative humidity Canchones

1.1 Stomatal opening

A B STR AC TI O N The capability of collecting water from the air humidity is an interesting way of providing water where there is a intense need specially when noticing the high deterioration on the hydrological systems of the area. Both the collection and the storage methods are highly efficient in this specific environment, reducing the water loss susceptibility when optimizing the capture - evaporation ratio and been able to sustain a growth development healthy enough for the biological system to last in time. This ratios will be explored later when developing the system of collection , storage and distribution.

moist air

dry air

moisture storage in the soil

1.1 Capture and Storage

CACTUS

CAC T U S GEO M E TRY The overall geometry of a cactus can be interpreted as a natural system in which every component collaborate for the creation of conditions that allow the plant to survive. This happens mostly saving water and not to let it evaporates. The extreme climatic conditions of the Atacama Desert and of the dry regions in general, make those strategies necessary for the flora to survive. We can see them applied both in the shape than in the proper behaviour of the cactacae. We will here explore the most important characteristics that can allow us to understand how to create the design of the new settlement having the same needs of saving the most of the possible water. The way in which this plant, belonging to the species of the succulent, create conditions to allow the growth could be synthesized in the formation of a surrounding micro climate that reduce the temperature and the control of the solar radiations. In this way less water is vapourised from the surface skin and therefore,

1.1 Copiapoa Cactus

Behaviour

Sphere 50 % enlighted surface

Coastal areas of Northern Chile. It's a very drought tolerant species. Despite the lack of rain where it lives, the extreme aridity is attenuated by the frequent dense coastal

Cactus 30 % enlighted surface

the plant is able to sustain its water reserves.

SO L A R GEO M E TRY STR ATEGY The vertical pleated surface of the majority of succulent species is particularly efficient to create an additional shadow surface that will helps the cactus to contol the temperature and the evaporation of water. The received solar radiation is 20% less than in a smooth spherical geometry which is also efficient because it allows the auto shadow which also helps in monitoring the temperature. So both the spherical arrangement and the pleated surface Humidity 100%collaborate for the same goal. This strategy could 90%be inspiring for control of the sun light exposure in a 80%building scale. 70% 60% 50% 40% 30% 20% The design of the globose species presents a 10% pleated surface that have an effect on the wind 0% 12:00 16:00 20:00micro 24:00turbulences 4:00 8:00 in12:00 behaviour creating the 16:00

W IND GEO M E TRY STR ATEGY

Smooth sphere Low amount of drag, thick wake

Cactus High amount of drag,

CO NC LUS IO N This adaptive behaviour of the plants could be very informative and relevant as strategies to cope with desert climates.

corrugations and in the behaviour of the air flow % stomatal opening Junoy shape. after meeting this body % stomatal opening Canchones % relative humidity Junoy % relative humidity Canchones

CITIES AND FARMING

1.1

11 After industrialisation, everything changed. With the arrival of the railways, along with inventions such as canning and freezing, it became possible for the first time to build cities more or less anywhere and any size 1.2 This next city, whilst you canâ&#x20AC;&#x2122;t see a lot of it is actually a map of the city Brussels in medieval time. After looking at quite a few maps the common feature of them is to have a wall surrounding the city as well as a moat. There is also

1.3 Thunen model

1.1 Star footprint

Water Convergence

B RIE F H ISTO RY O F AGRICU LT U R E A ND H U M A N SE T T L E M E NTS It is widely thought that, ten thousand years ago the human hunter-gatherer began to permanently settle in the Fertile Crescent where abundant food was cultivated such as cereals and husbandry. This process of cultivation near the settlement has markedly shaped the human civilisation forever. At the time, urbanism and agriculture were thought to be created. Examples of urban and agricultural innovations were firstly observed during the Sumerian civilisation. After the flooding of the Tigris and Euphrates, the Sumerian took this opportunity to develop the Irrigation system to enhance the productivity of the lands. Thus, the agriculture system becomes more complex with the abundant harvest. Food had to be stored and distributed to the settlements and increased in complexity as it expanded. New system of trade exchange emerged between the Romans and the Greeks. Wine and oil were produced by the Greeks and expensive and high quality fruits and vegetables were cultivated in the wild Roman lands. The inhabitants of Rome were sustained by the grains that were brought from the invaded territories by the see. Until the pre-industrial period, food transportation was only possible by the see. This becomes a major constraint to the city development. Thus, the city struggled to feed its growing population.

surrounded by empty, unused land. He adds, the land of the State is completely homogeneous. Thus the land doesnâ&#x20AC;&#x2122;t have rivers, mountains or anything blocking the continuity of the main surface. Moreover, there are no primary transportation network branches. Thus, every farmer was responsible of getting their way to the marketplace and could do whatever they could in order to profit as much as they could. Thus, the rings where distributed as follow:

1. Fog phenomenon, called Camanchaca Copiapo,Chile by laurent abad in Atacama Desert

1. Dairy and market gardening; 2. forest for fuel; 3.grains and field crops; 4.ran

20T H C E NT URY R EAC T IO N TO T H E INDUST R IALISAT IO N The Pre-industrial city system was compact and tightly organised in such a way that cultivation lands were boundaries to the city development. After the industrial revolution, the city was relieved from the constraints that ThĂźnen expressed in his model. The transport commodities and the railways, along with inventions such as canning and freezing allowed transportation of people, food and even livestock. However, it has decentralised the city and privatise the land. Farms become far away from the city. Reactions to the industrial city model attest that it has detriment the relationship between people and nature, but also their common interest, Food.

TH E ISO L AT E D STATE Before the industrial revolution, Johann Heinrich Von ThĂźnen proposed a new agricultural land use model. He stated that the market value of land, the price of agricultural commodities and cost of transport should lead to a general spatial distribution of the land around the city. This model was based on a series of land use rings but started from a series of assumptions1. Firstly, the model propose to have a central market located within the city, looking for a community which was self sufficient and has no external influences. Then,

Domain

1.1 After industrialisation, everything changed. With the arrival of the railways, along with inventions such as canning and freezing, it became possible for the first time to build cities more or less anywhere and any size

1.1 A painting showing the arrival of the railways, allowing the transport of people, food and livestok.

1.2 Howards’ , ‘Garden cities of ‘Tomorrow’

1.2

1.3

GA RD E N CI TI ES O F TOM O RROW As a reactions to the industrial city, Ebenezer Howard in his book ‘Garden cities of ‘To-morrow’ suggest a ground breaking concept. He proposed an alternative to the degraded living conditions that were caused by the industrialisation. Howards’ model was a complete contrast to the 19th century metropolis. He was clearly inspired from the previous city system described by Thünen of the medieval European city where urbanisation and agriculture were bounded together as a unique system. Howard wanted to compound both advantages of town and the countryside by ensuring an interconnected relationship between city-states that were linked to farming communities, collective farming lands were the profit returns to the communities. However, Howard’s project was realised but failed in its original intentions, critics argued that it was a form of urban expansion toward the countryside.

After industrialisation, everything changed. With the arrival of the railways, along with inventions such as canning and freezing, it became possible for the first time to build cities more or less anywhere and any size

Howards’ , ‘Garden cities of ‘Tomorrow’

Multiple propositions were also developed to react to the industrial city. But they could not ignore the fact that the industrial revolution has markedly changed people’s lifestyle. Therefore, it was difficult to ignore the inextricable relationship of the new urban features and the lifestyle dictated by the industrial wave.

URBAN AND AGRICULTURE DISTRIBUTION

Juval PORTUGASLI Han MEYER Egbert STOLK Ekim TAN ‘Complexity theories of Cities have come of Age’ Springer Edition ‘Complexity Routledg

Conf 01_ Concentrate Urban morphology

http://www.nydailynews. com/new-york/ nyc-housing-projectlot-turned-farmarticle-1.1376459 NYC housing project home to first of 6 new urban veggie farms The acre-sized plot ushers in urban farms planned for public housing projects.

Conf 02_ Diffuse Urban morphology

Vertical farms

Fin Conf_ Diffusion of concentrated urban morphologies

Juval PORTUGASLI Han MEYER Egbert STOLK Ekim TAN ‘Complexity theories of Cities have come of Age’ Springer Edition ‘Complexity Routledg

URBAN AND AGRICULTURE DISTRIBUTION

IN T ROD U C TI O N

UR BAN FAR MING

The cities through their evolution partly lost the idea of integrating the cultivations in their geographical boundaries. We will study the two main strategies of distribution and their combination in the creation of a third new model.

800 MILLION PEOPLE WORLD-WIDE ARE INVOLVED IN URBAN AGRICULTURE AND CONTRIBUTE TO FEED URBAN INHABITANTS. IT IS PREVIEWED THAT IN 2015, 26 CITIES ARE EXPECTED TO HAVE A MORE THAN 10 MILLION POPULATION. TO FEED A SO HIGH NUMBER OF INDIVIDUALS AT LEAST 6,000 TONNES OF FOOD MUST BE IMPORTED EVERYDAY.

CONCE NT R ATE U R BA N M O RP H O LO GY This conformation of urban settlement is spread in the world for more than a reason. Ancient examples are found in the Middle East where this design where used mostly in the area of qanats distribution where the water was driven from the mountains to the agricultural fields then to the residences. The official regulation of this phenomena occur in United Kingdom around the years 1950 where this strategy became law. It is not accurate to speak about those green belts just in an agricultural sense but the idea of surrounding the urban settlements with green spaces was yet existing.

D IF FU SE U R BA N M O R P HO LO GY The agriculture become in a diffuse urban morphology part of the living settlement and subsequently of an urban space. This strategy was the naturally configuration of the rural areas and the primordial system of generation of the urban settlement. This morphology was still emerging until the middle age where the property of the land were in the hands of private owners which made harder the process of expropriation and increased the urban patch value. Today the tendency is to try to reintroduce those principle of integration of the agricultural areas in the cosmopolitan context. Different are the expressions of this new rural molecule in the genome of the metropolis. The urban farming is one of the applied strategies of a contemporary attempt to repropose the concept of diffuse urban morphology.

The Urban agriculture can be identified as the balancing element of those data. This strategy can be identified as the cultivation, processing and distribution of food in built-up intra-urban areas. The idea of supplemental food production beyond rural farming operations is not new. Different applications of this concept are actually happening, in New York, with as a composting governement program available to urban gardeners and farmers; in Mumbai, where Dr. Doshi's city garden methods are revolutionary for being appropriate for reduced spaces as terraces and balconies. Other natural resources as the water can be conserved with urban farming.

1. Stephen MARSHALL ‘Cities design & evolution’ Routledge, Taylor and Francis group

2. Juval PORTUGASLI Han MEYER Egbert STOLK Ekim TAN ‘Complexity theories of Cities have come of Age’ Springer Edition ‘Complexity Routledg

DIF F US IO N O F CO NC ENT R AT ED UR BAN M O R PH O LO GIES The new system proposed take into account the two strategies of distribution of the agricultural spaces within the city to newly reinterpret the idea of centralization, and diffusion. The new concept of convergence is rethought in a neighbourhood scale. The concentration of the agricultural plot in a same footprint allow the centralisation of our nutriment surrounded by the residential areas. This configuration born from the exigence of dividing the 'food production centres' in smaller centralised reality in order to assure their water independence through the fog catchers. The diffusion of concentrated urban morphologies also allows an easy reaching of the patches centres or production nodes from all the users. cells, each with their ‘green’ centroids.

FARMING METHODS: CLIMATE CONTROLLED AGRICULTURE GR E ENH O US E

1. Vermeulen, P., 2010. CO2 dosering in the biologische glastuinbouw.

Its an enclosed controlled interior environment made of a glassed structure capable of letting the sunlight to get to the plants and storing the heat and the CO2 promoting a higher growth rate in plants. During summer, when it gets too hot, windows get open. Therefore to avoid the CO2 loss, it is controlled by calibrating it artificially1.

1.1 eponline.com

H Y DRO PO NIC 1.1 Industrial greenhouse 1. FAO. 2006. The State of World Fisheries and Aquaculture

Hydroponic use water instead of soil as a root growing environment including nutrients solutions. It is highly productive using less water an land but it needs more technology. It is mostly grown in enclosed enviroment controlling the different factors that affect the growth.

AQUAC ULT UR E

1.1 waterkenya. wordpress.com

1.1 Hydroponic cultivation 1.1 www.environmentalwatch.com

It relates to the farming of water organisms such as fish, crustaceans, molluscs and aquatic plants. Aquaculture cultivate in fresh water as well as in salt water under controlled conditions that can increase populations and avoid the interference of predators. About one third of the overall production of fish comes from Aquaculture1.

AQUAPO NIC S Aquaponics is the combination of Aquaculture and Hydroponics. Thus, wastes produced by the fishes serve as nutrients for the plants and at the same time the remaining used water that plants don't absorb can be use as food by the fishes.

1.1 Aquaculture cultivation 1.1 aquaponicsfish. landscapeideasand picture.com

1.1 Aquaponics

AQ UA P ONI C S

PLANTS

Aquaponics is essentially the combination of Aquaculture and Hydroponics. Both aquaculture and aeroponics have some down sides, aereoponics requires expensive nutrients to feed the plants, and also requires periodic flushing of the systems which can lead to waste disposal issues. While re-circulating aquaculture and aereoponics are both very efficient methods of producing fish and vegetables, when we look at combining the two, these negative aspects are turned into positives. Research has shown that an aquaponic system uses about 1/10th of the water used to grow vegetables in the ground, so it can be incredibly productive.

Research has shown that there are over 300 plants that would grow well in an aquaponics system, depending on location, climate and a variety of other factors. Root plants are definitely worth avoiding, as they’re known to be sensitive. The best crop though are herbs and green leafy vegetables. We can easily grow cabbage, cauliflower and broccoli. And with enough care, salad vegetables, Aquaponics systems can in fact easily grow varieties such as lettuce, cucumber, and red onions. Tomatoes are also easy to grown in an aquaponic system together with Aubergine, beans and peas.

1. http://www. backyardaquaponics. com/ guide-toaquaponics/what-isaquaponics/

1. FAO. 2006. The State of World Fisheries and Aquaculture

ST RAT EGY The plants extract the water and nutrients they need to grow, cleaning the water for the fish. By using gravity as a transport, water is drained from the fish tank into a gravel bed where there are bacteria that live on the surface of the growbed media. These bacteria convert ammonia wastes from the fish into nitrates that can be used by the plants as fertilizers. This process take the name of “the nitrogen cycle”. On the gravel bed, we also use watercress as a secondary means of water filtration. The filtered water is pumped from the gravel bed to the growing beds, where we raise a variety of crops. The water is wicked up to the vegetables roots.

FISH ES Many different species of fish can be grown in an aquaponic system, and your species selection will depend on a number of factors including local regulations. Quite high stocking densities of fish can be grown in an aquaponic system, and because of the recirculating nature of the systems very little water is used. Other aquatic animals that can be incorporated into an aquaponic system are mussles, which are filter-feeder, and so they're able to clean the water, fresh water prawns, and fresh water crayfish. Crustaceans can also be an addition to an aquaponic system.

FARMING METHODS: TRADITIONAL FARMING AND WATERING SYSTEMS CO NV E NT IO NAL

1. Water Center for Latin America & the Caribbean

Although the traditional farming methods have been optimizing in relation to the productivity of the planted surface as well as in water usage terms, the methodology is not capable to adapt to arid climates where there is a critical scarcity of water. Is probably a profitable way of producing food but it costs to much to the hydrological systems being the more deteriorated and exhausted actor of the system of food production1.

1.1 www.gwpchile.cl

S UR FAC E The surface watering method is implemented as ponds or streams. The water normally moves because of gravity, according to slopes naturally generated or artificially created. Furrow, border strip and basin irrigation area are the most common methods, where the last one is more commonly known as flood irrigation as the fields usually get flooded. 1.1 Convential Farming in Atacama 1.1 www. irrigationmuseum.org

The drip irrigation system is currently the more popular method used in permanent crops. It works as the name says, letting the water fall drop by drop at or near the roots of the plant. They can be either in "point" or "line" configuration. This is consider the most water-efficient method of irrigation since evaporation and runoff is minimized.

1.1 Furrow irrigation system 1.1 marquettefood.coop

1.1 Line drip irrigation system

DR IP SYST EM

SP RINKL E RS

1. Myers, J.M., C.D. Baird and R.E. Choate. 1970. Evaporation losses in sprinkler irrigation.

With more technical watering systems the losses have been reduced but there is still a high evaporation rate where for example in a high tech evaporation sprinklers the water droplets sprayed through the air get evaporated according to: (1) the climate demand; (2) the time available for evaporation to occur; and (3) the surface area of the water droplets1.

1.1 xsgh6688.en.madein-china.com

FOG COL L EC TO R In places with enough relative humidity in the air, specially where there is consistent fog, water is captured using big polypropelene nets to intercept the fog in order to get the water droplets from the clouds and then store the water for using it later in agriculture.

A IRD ROP

1.1 Sprinklers irrigation system 1.1 poleshift.ning.com

Similarly than the previous one, it filters hot environmental air through a small turbine, feeding it through a copper serpentine tube system and then into the earth where it cools and releases moisture which is stored in an underground container. The dry air is then re-released into the atmosphere and the collected water pumped through semi-porous hoses to the plant roots. 1.1 Fog capturing system 1.1 technabob.com

1.1 Airdrop system

TRADITIONAL WATER COLLECTION SYSTEM QANATS

38 mt- 45 mt 8 046 mt- 48 280 mt

Mountain chain

Groundwater recharge

Agriculture

Urban settlement Top view Qanat development

Mountain chain

Urban settlement Section Qanat development

Source: Abdel Haleem, M. 1989. Water in the Qurâ&#x20AC;&#x2122;an. Islamic Quarterly/33 Source: http://unfccc.int/files/ meetings/workshops/ other_meetings/ application/pdf/121103_ iran.pdf

Water Convergence

ST RAT EGY A Qanat is an ancient mode of irrigation that in Iran can be affiliated to the Achaemenian period and can be said to have a sustainability of nearly 3000 years. The qanat relies entirely on passive tapping of the water table by gravity. Through this method water present in the aquifers is drawn to the surface in order to be utilized by manipulating a series of vertical wells and one horizontal well. This method uses no electrical or fossil energy. The length of the qanats is about 5 to 10 km long with its shaft positioned on average every 25 mt, minimum distance to allow a comfortable construction and a good ventilation. This methodology rests on indigenous knowledge. The underground flow of the water minimize the extensive evaporation which lead to a considerable water loss, avoid any contamination and prevent damages in case of floods and earthquakes. The qanats are integrated with the kariz, smaller subterranean channels that allow the distribution to the cistern of individual buildings.

DIF F US IO N

1.img source: http://www.livius.org/q/ Iran is considered the birthplace of qanats, with the qanat/qanat.html expansion of Islam another major diffusion of this technology starts. During the Roman-Byzantine era many qanats were constructed in Syria and Jordan. The Arab invasions spread them all across North Africa,Spain, Cyprus, and the Canary Islands.

DE V E LO PMENT Since 1950s motor-equipped wells have succeeded in replacing qanats. In comparison to them, wells have a shorter life span whereas, qanats can hold good for centuries. Excavation of such wells has further led to the drying up of water table. Agriculture and participatory productivity systems based on qanats have been so almost disappearing. The massive exploitation of the water table is an issue in the contemporary scenario of the Atacama region and the idea of not to damage it anymore lead us not to introduce this collection water technique in our project scenario.

1.1 A qanat near Anšan, Iran 37

WATER COLLECTION METHODS FOG CATCHERS FO G

Camanchaca, the typical coastal clouds of the Atacama Desert Inversion layer and clouds prevent moisture from entering the desert Source: http://www. atacamaphoto.com/ search/index.php?/

1.1 Fog catcher system

The fog is defined to be the result of cloud when it embraces the ground surface. According to Schemenauer et al (1988) there are various process of fog formation. However, the most relevant for harvesting technology are essentially, Advection fog that appears when the clouds in the subtropical SE pacific ocean are advected by the wind to the coastal mountains. Orographic fog is produced during the cooling of massive humid air when transported uphill. Fog consists of tiny liquid water droplets from 1 to 40 micrometers (μm) in diameter. The average droplet diameter is 10 μm. Thus, a minimum fog season duration of half a year might serve as a guideline when considering the feasibility of using this technology for water supply purposes.

FO G C ATC H ERS T ECHNOLOGY Fog collection method has been proved to be a sustainable and simple technology to provide fresh water for drinking and plant watering.

The first “fog collectors” were installed in Chile, at Chungongo, one of the driest places in the world A hundred polypropylene net panels, 4 metres high by 12 metres wide, collect 1an average of 5,000 litres of water a day.

The fog harvesting system consists of a single or double layer net with variable sizes mainly large and standard fog collectors (LFC and SFC). The material used for the nets is mostly polypropylene but can also be made of nylon or polyethylene, that have properties to catch the fog and release it to the gutter without absorbing it. The material and mesh density along with the size of the panels may affect the quantity of water collected. The nets are supported by two legs and cables to help the system stand.

10 m

Wind

E XT ENT O F US E Fog harvesting system to obtain fresh and clean water has been widely investigated for more than thirty years and has been achieved with success in the coastal mountain of Chile, Ecuador, Mexico, and Peru. Because of a comparable climate and mountainous conditions, this technology also can be realised in other similar regions. However, the water outcome may vary from a place to another.

Gutter

Drainage system

Storage system

T Y P ICA L WATE R H A RV EST The quantity of water harvested from fog depend greatly on the size and number of fog collectors installed. Also, the rate of harvest proper to the location, varying daily and seasonally from a site to another. However, the typical harvest estimated by Fogquest organization is between 200 and 1000 litres per day. For instance, with 100 LFC (4000 m²), at El-Tofo, Chile, an average of 15 m³ per day was produced.

WAT E R Q UA L I TY According to Schemenauer and Cereceda (1992 a,b) the water harvest from fog concord with the world health organization (WHO)drinking water standards.

ECO NOM IC A S P EC T According to Fogquest organisation, the price depends on the size, the quality of the material used, labour and location of the site. For instence, they estimated The Large fog collector (LFC) of a 40 m²to cost between $1000 and $1500 that would last 10 years.

1.1 The South African fog water collection project is spearheaded by Prof. Jana Olivier, in association with the University of Pretoria, the Water Research Commission and UNISA. Fog as a source of water, under ideal conditions yields 3800 liters per day.

1.1 Fog nets on are placed on the hillside to catch the moisture and provide precious water to the village of Bellavista, about 10 miles (16 kilometers) outside of Lima, Peru. Photograph by Anne Lummerich

Domain

CONTEMPORARY CITIES AND FARMING

V ERT IC AL FAR M S The vertical farm represents a consistent potential of growing and feeding locally the urban population. Dr.Despommier, professor at Columbia University has been developing the concept for almost 20 years. He demonstrates that this farming method work as a closed loop to grow food, recycle water, produce fish and natural fertiliser and also generates energy. He proposes this concept with a 150 farming tower able feed the inhabitants of New York city. Dr. Despommier suggest that the farming and harvesting in these vertical farms should be highly mechanised. He argues that these towers might have rounded shape and transparent in order to allow the sunlight penetration into the entire floorplate. Moreover, water runoff is filtrated and then used to irrigate the vegetables and fruits but also grains. The vertical farm is also adapted to produce fish, poultry and pigs. Wastewater is recycled to be reused for drinking or cultivating fish which will also generate natural fertilizer for the plants and heat energy.

PIG C IT Y The concept of the pig city in the Netherlands as proposed by MVRDV consists on the concentration of pig farming in a multiple storey towers. Grains are also cultivated in order to feed the pigs that in turn generate fertilizer from their waste. This concept is beneficial in terms of optimising the use of the land, but also to reduce the travel distance to distribute the production.

S USTAINAB LE C ITIES Contemporary cities such as Masdar in Abu Dhabi, in the United Arab Emirates, do not fully comprehend the criterion that are required to make the city sustainable. Food production strategies for instance are essential to address the issue of climate change directly related to traditional farming methods that are no longer efficient but also threaten the world food security.

This part discuss the new approach that should be taking place in terms of food production and consumption in order to make efficient and sustainable cities with major concern about the world food security that is today highly threatened. It is also essential to preserve the biodiversity in terms of vegetables and fruits in order to cope with single failures and diseases susceptible to occur among the food chain (Edible infrastructure).

CONCLU S IO N The vertical farms as suggested by Despommier, might rely on certain technologies such as artificial lightening and climate control assessment. This may engender high capital investment, but has certainly positive environmental impact on the balance of the ecosystem and the balance of the society. However, It is essential that these towers adapt to the context enviroment, by considering the climate and the culture of the place. The glass faรงades in the towers for instance might not suit certain climate with high solar radiation.

1.1 http:// arquitecturamexico. wordpress. com/2011/12/06/ciudadmasdar-una-ciudadsustentable/

P ROP O SA L The prediction of the population growth is developing at very high rate and is estimated to reach 10 billions in 2050. At the same time, urban population is expected to soar and attain 6.3 billion in 2050. We genuinely believe that is fundamental to explore alternatives for people to settle somewhere else. Desert lands for instance remains empty and cover one third of the earthâ&#x20AC;&#x2122;sâ&#x20AC;&#x2122; land surface. However, building cities in the desert implies providing water to the inhabitants to survive in these arid lands.

1.1Sources: WWDR 2012 - See more at: http://www.unwater. org/statistics_urb. html#sthash.U3L4PQEB. dpuf

Therefore, our research aim to design an urban settlement with an autonomous water system that would sustain 25 000 people and integrating agricultural production. We decided to work in the driest desert in the world Atacama desert in order to explore extreme conditions and find adaptation strategies to cope with the harsh environment and yet provide all the needs for the inhabitants in terms of water and food. Hence, our ambition is to proof the feasibility erecting a new settlement that would be as self-sufficient as possible by avoiding as much as possible the use of ground waters and aquifers of Atacama region and rather explore the fog catchers system as an integral part of the city. Therefore,we investigate the use of Camanchaca (local name of fog phenomenon) as a source of fresh water for domestic use and agriculture irrigation. However, the fog catcher system as initially designed might be land consuming. Hence, it is fundamental that the settlement would integrate the fog catchers within the buildings in order to optimize the land use and produce locally water and food for the inhabitants. Parallel to that, salinization and desertiďŹ cation of agricultural lands in the driest areas constitute an important issue to address by finding the most suitable farming methods to make the settlement sustainable and as self sufficient as possible.

Introduction

CURRENT HYDROLOGY IN ATACAMA DESERT

WAT E R S C ARC IT Y IN THE DES E RT O F ATAC AMA

7 http://www. dailymail. co.uk/news/ article-2301226/ Fog-catchersattempt-harvestmoisture-hugenets-Chileandesert.html

Atacama desert

6% 7 Farming water demand in the atacama desert is 12 times bigger than the amount of water for domestic use; industrial use and copper mining also consume a huge amount of water.

Human invasion with little regards to the environment and its ecosystem, disturb profoundly the hydrological cycle in the Atacama desert. Hence, abundant amounts of water have been pumped at very high rate for agriculture purposes (73%), Industrial use (12%), mining activities (9%) and domestic use (6%), leaving the water basins empty (Chart 1.3). For along time the region of Atacama relied economically on agricultural activities. Most of the inhabitant are farmer or

12% 9% 73 %

Potable Water

Industrial use

Mining activities

Agricultural irrigation

1.9 Water consumption in Atacama desert

Atacama Desert, with no rain recorded for hundreds of years, is considered to be the driest place in the world. The aquifers and rivers are dry not only because of the lack of recharges but also because of the evaporation process in the area. Today the situation is alarming due to continuous and high water extractions for human use without concern about the balance of the ecosystem.

WAT E R BAS INS The Water Centre for Latin America & the Caribbean conducted a research regarding the hydrology in Atacama desert. According to the study, most of the water available in the region has been over used exceeding the normal pace that would keep the balance with the recharge.(Chart 1.5). Experts in water assert that, â&#x20AC;&#x2DC;water crisisâ&#x20AC;&#x2122; is mainly caused by the significant growth of population and probably not as a result of climate change as we might think. Over 70% of the water is used for agriculture combined with domestic use they represent a considerable amount of water extracted that can lead to water shortage.

CONCLU S IO N

8 Map showing the water basins in the Atacama desert.

Atacama desert is facing an enormous stress in terms of hydrology. Therefore, it is urgent to develop new methods that would minimise the actual consumption. For instance, harvesting water from fog represent a unique alternative for the water crisis in the region.

1 m³/s

The Atacameños were, in this way, the first sedentary town in Chile and at the same time the first one that practiced the agriculture. They builded terraces at the foot of the hills for making their crops in this difficult land, the terraces were watered in artificial way and fertilized with guano of alpaca and llama. In this way the agriculture became the main source of the economic activity in the region; among its crops emphasize maize, beans, pumpkin, potatoes, cotton and others.

1,28 m³/s

1,9 m³/s

Other important economic source was the cattle, they used the meta and the wool of alpacas and llamas; these animals were at the same time the main mean of transportation for the locals which let them to make the “trueque” (exchange) with the neighbour towns.

50 km

Their notable art was expressed in their weaves, pottery and wood carve, copper and bronze.

1.8 Map showing the water basins in the Atacama desert.

4,0

9 Graph showing the Basins extraction ratio reference

3,0 2,5 2,0 1,5 1,0 0,5 sc o Hu a

pi ap

a Lo

ug al ar

sé Jo n Sa

Ta m

0,0 Llu

Extraction / Recharge

3,5

1.9 Graph showing the Basins extraction ratio.

FOG PENETRATION IN ATACAMA DESERT

A 50 km

FOG

50 km

FOG P E NE TR ATI O N 1- JunĂn - Zapiga

28 km

2- Alto Hospicio - Humberstone

33 km

3- Punta Gruesa - Pozo Almonte

Map showing the fog distribution and in the coastal mountains of Atacama desert and locating the corridors in northern part allowing the fog to penetrate to the inland of the desert.

32 km

4- Patache - La Tirana

45 km

5- Guanillos/Chipana - Salar de Llamara

38 km

5500 m 5000 m 4500 m 4000 m 3500 m 3000 m 2500 m 2000 m 1500 m 1000 m 500 m 0m 0 km

5 km

10 km

15 km

20 km

25 km

30 km

35 km

40 km

45 km

SectionA Standard situation of fog propagation in the coastline of Atacama 15 L

7.5 L

5500 m 5000 m 4500 m 4000 m 3500 m 3000 m 2500 m 2000 m 1500 m 1000 m 500 m 0m 0 km

5 km

10 km

15 km

20 km

25 km

30 km

35 km

40 km

45 km

Section B Fog penetration in corridors_Atacama

46 1.1

CO NC LUS IO N

Recent studies have been conducted in the Atacama region in order to quantify the water harvested from fogs. It has been recording constant amounts of dense fog from June to December every year yielding an average of 10 litres per square metres a day, which make Atacama Desert idyllic place to apply this approach. Another research shows that dense fogs concentrate at high altitude in the coastline but, slowly dissipate to completely disappear in the inner land. However, another research affirms that, corridors in some parts of the region allow the fog to penetrate and reach considerable amount of fog. The water harvest reduces to 7.5 litres per square metre per day.

We strongly believe that the fog represent a valuable source of water in the Atacama desert. Fog collection system has been experimented for a long time and gave accurate data that would endorse our research to implement the needs of our target population.

L/Sqm/d

FOG IN ATAC A M A DES E RT

30 25 20 15 10 5 0 S -5

N J M M

1997

S N J M M

1998

S N J M M

1999

We would like to achieve an autonomous and sustainable system using mainly the fog as the major source of water. Considering the arid climate of Atacama, it is crucial for our research to investigate cities that have been built in similar environment and comprehend their way to adapt to the harsh climate, before going to experimenting the potential of fog in the site study.

S N J M M

2000

J S N J M M

2001

J S N J M M

2002

J S N

2003

J M M

10 Fog phenomenon, called Camanchaca Copiapo,Chile by laurent abad in Atacama Desert

11 SOURCE: (P. Cereceda, H. Larrain, P. Osses, P. Lรกzaro, R. Pinto & R.S.. Schemenauer)

J S N

2004

The graph demonstrate the persistence of the fog phenomenon in the Atacama Desert every year for a period of 6 months. The average water harvested is around 10 liters a day.

1.10 Fog phenomenon in Atacama Desert

Domain

Chapter Two

Methodology

CITIES CASE STUDIES

Calama, Chile Author: Cobreloino (Creative Commons Attribution 3.0 Unported) Source: http://www.myworld-travelguides.com/ calama-chile.htm

Kachan, IranSource: http://www. traveljournals.net/ pictures/285784.html

IN T ROD U C T IO N We started looking at examples of cities in arid climate in order to understand and extract relevant data that would guide us in the design process. Being in the desert, the main concern is water. therefore, the case study were focusing on methods of collecting and managing efficiently water. The Qanat system was widely used in desert cities all over the world and are thought to be originally from Iran. For that reason we decided to study the example of Kashan city in Iran that integrate this method.

The food production is also our main issue in this research. Today agriculture and the city constitute two different systems which result in waste of energy. moreover, traditional methods are thought to be inefficient in terms of water consumption. The city of Calama located in the inland part of desert of Atacama represent an example of early human establishment in the desert with agriculture as the main activity. .

CASE STUDY 01 CALAMA-ATACAMA DESERT CALAMA CITY, ATACAMA DESERT The city of Calama is located in the province of Antofagasta, in the inland part of Atacama desert. The compact urban settlement gathers around 143.000 inhabitants. It is built in the Loa river. Therefore, the city of Calama relies essentially on farming. It is a typical example of pre-industrial city model where the city is surroundded with agriculture production.

MINING AC TIVITY The emergence of mining activities in the region of Calama have helped significantly the expansion of the city along with the demand of water.

Calama

1Km

1 1.1 Calama city map

Souce: http://www. weatheronline.co.uk/

However, regarding the scarcity of water in the region, Calama is threatened to disappear since the water extracted for Farming represent 73% of the total amount available. The industrial and mining activities in the region are also participating to the continuous extraction of water basins. Data: Surface area: 15,596.9 km2 Population: 143,000 Altitude: 2,300 m min temperature: 3 째C max temperature: 23.4 째C Average Temp: 13.2 째C Precipitation: 1 % Humidity: 15% - 78% Wind speed: 8 m/s Wind direction: W, SW, E

Calama - Chile By Rita Willaer2 Source: http://www.flickr. com/photos/14417999@ N00/7048328967

1.2 Calama agricultural village

Chuquicamata copper mine Author: Reinhard Jahn, Mannheim (Creative Commons AttributionShare Alike 2.0 Germany)

CONCLU S IO N It seems to be obvious that conventional method of farming can no longer persist in the Atacama desert. The water has been extracted at very high rate mainly because of agriculture. Therefore, it is urgent that new strategies for farming need to be adapted. Otherwise, the situation may become worst in the near future. There is growing evidence that new method of farming are substantially more efficient in terms of water and land consumption

1.3 Copper mine in Chuquimata, Calama

CASE STUDY 01 CALAMA-ATACAMA DESERT CALAMA URBAN TISSUE The city is well connected to the surrounding cities. This may suggest the distribution of food to the other settlement. The network analysis of the small patch, shows the existence of two patterns, irregular one and a the rectangular grid separated by the main network that seems to be initial boundary of the city. The expansion of the city clearly developed toward agricultural fields.

0 50 m 100 m

300 m

500 m

Urban morphology tissue Main network

Min street width = 5 mt Max street width = 17 mt CALAMA PATCH SAMPLE Average street width = 9 mt Looking further to the blocks, their size were the smae in the entier patch (120*60) sqm, the buildings present irregular shape and a chaos organization. The urban morphology of Calama city do not seem to reflect any response to the environment and the culture of the region.

Secondary network

Conclusion Number of building= 666 Min footprint area= 7 sqm Max footprint area= 760 sqm Avg footprint area= 383.5 sqm Built area= 32478.05 sqm Unbuilt area= 57521.95 sqm Built %= 36% Min street width= 2 mt Max street width= 9 mt Average street width= 6 mt

0 30m 60 m

180 m

300 m

Patch sample

8 km

4.0

2.2

0.5 0

Calama

1Km

CONCLUSION This city before and how it becomes and how we want to respond to, it is evident that Calama city big road

Calama - Chile By Rita Willaer2 Source: http://www. flickr.com/photos/ rietje/7048331951/in/ photostream/

Caspana is a Chilean village located 85 km northeast of the city of Calama, in the gorge carved by the river that shared its name and that is a tributary of the Salado River. Agricultural terraces form part of the landscape of the area.

Method

KASHAN

N Water supply

IRAN

Max Temperature = 42 C째 Minimum temperature = -5 C째 Average temperature = 20,2 C째 Maximum Rainfall = 27,9 mm/month Minimum Rainfall = 0 mm/month Yearly Average Rainfall = 103,1 mm Humidity = 46 % Wind Speed = 2,25 m/s Agricultural plot= 25 sqkm Urban plot = 34 sqkm Agricultural areas per capita = 100,49 sqmt

Source: Institute of Geog Catholic University of Ch Wind direction

1.1 Urban Development of the city of Kashan Mountain Chain

Agricultural plots

Kashan

1.1 Water distribution in Kashan 58

Water Convergence

graphy, hile

IN T ROD U C TI O N To the northeast of the well-watered mountain ranges of western and southern Iran, a line of oases which have given rise to important urban areas stretches along the bordering of the desert basins of central and southeastern Iran. The city of Kashan is located in the province of Isfahan, the site is linked to a great spring close to the village of Fin in the southwest of the city, which supplies the continuously flowing watercourse of the whole area along the mountains; otherwise only seasonally flowing torrents are to be found. The growth of the urban morphology has a vital relation with the collection and distribution of the water. Being in a climatic region associates with arid climate the method of distributing and managing the water resource is more than crucial. The creation of the qanats along the base of the mountains determine the position of the agricultural fields and the development of the urban settlement. The city layout is evolving in the axis perpendicular to the mountain chain along the development of the qanats that intercepted the

underground water from the water table.

QANAT The flow of running water was quite insufficient to maintain a significant extension of the oasis. The qanﾄ》 had long since become the principal source of water. In 1960 they were the main water supply in 180 towns in the province, while only 42 were supplied by surface water. But now it had already been more than 50 years since any new qanﾄ》 had been build. Anyway the amount of water collected with this method manage to sustain a daily water consumption of 150 lt per habitant and totally more than 248.789 litres per day for the whole population. Not only, Kashan also managed to became the third Persian producer of Damascus Rose flowers.

1. P. Cereceda, H. Larrain, P. Osses, P. Lﾃ｡zaro, R. Pinto & R.S. Schemenauer)

2 http://www. iranicaonline.org/ articles/kashan-v1urban-design

AQUIF ERS Unfortunately the environment is paying the consequences of a so intensive exploitation of aquifers. In the semi-arid climate the absence of high rainfalls make increasing the development of the groundwater resources that leads to the overexploitation of the water table. The contamination of the groundwater with fertilizer is another result of the intensive agricultural techniques. The city of Kashan has annual domestic water consumption close to 24 million cubic meters. The sewer system nowadays mainly turned into absorption wells. 70% of domestic water returns to water resources as wastewater. Thus, this flow from the domestic and agricultural consumptions has been one of the principal sources of aquifer recharge. These return flows have contaminated the groundwater in the entire adjacent aquifer, main water resource in the area. Now the Kashan aquifer suffers from overdraft of water and it has increased in an annual groundwater table drawdown close to 1 meter.

1.1 Fin Gardens, Kashan, Iran 59

KASHAN

primary network secondary street pedestrian

1.1 Network Morphology

Min street width= 2.14 mt Max street width= 18.78 mt Average street width= 6.154 mt

Min Block area= Max Block area= Average Block area= Built area= 35.159 sqm Unbuilt area= 54.841 sqm Built %= 39% South facing facades= 11.302 sqm South facing facades ratio= 20.4 % Number of building= 482 unities Minimum footprint area= 12.84 sqm Maximum footprint area= 344.68 sqm Average footprint area= 84.33 sqm 0

30 m

60 m

180 m

300 m

1.1 Urban Morphology 60

Water Convergence

U RBA N M O R P HO LO GY

B UILDING T Y PO LO GY

Kashan city fabrics characterized by a network composed of narrow winding streets called koocheh with high walls of adobe. This urban design is an optimal form of desert architecture. This configuration of the urban pattern with narrow street and close urban fabrics manages to maximize daytime shades, and insulates the unity from severe winter temperatures. The same strategy is applied in order to avoid the presence of south facing facade. Their orientation it's 20% of the total facades in the patch, it results to be also efficient.

Almost all traditional Persian houses are designed with a central small pool with surrounding gardens. A specific orientation toward and away from Mecca is characteristic of the main facade. The traditional houses in the city of Kashan are designed to support a system of wind catchers that creates unusually cool temperatures in the lowest levels of the building. Thick walls were designed to keep the sunâ&#x20AC;&#x2122;s heat out in the summertime and retaining the heat in the winters.

The main network is generated from a central spine which follows the groundwater flow direction. From this arterial road the branches of the secondary network and the block patches started to emerge. To allow a rich wind flow the growth of the city occur modifying and redirect its morphology. This strategy is formulated to make the arsh temperature of the summer season tolerable. The absence of a comprehensive plan led to the subdivision of agricultural land into small plots for housing construction without allocating open spaces, sidewalks, infrastructures and utilities. The circulation is allowed exclusively for vehicular access with disregard for pedestrian needs and the balanced relationship with nature and the important cultural heritage of Kashan.

The wind tower is a tall structure which emerge from the roof over the pool. It has several directional ports at the top which by closing or opening in certain direction can control the ventilation within the structure below. The ways in which wind catchers were built was different according to the plans of the house unity. It probably contributes to the cooling operation collaborating with the relative courtyard, hall or saloon. Those last are directly connected with the wind catcher but from time to time this link is provided through and alternative space. Based on their position on sites on top of roofs in different houses and their interaction with original spaces of aestivation ward and courtyard, the wind catcher can be divided in three types: X-form blades, Y-form blades and shaded blades.

Source: http://www.defence. pk/forums/iraniandefence/235985-iranianwind-catchers. Img_01 source: http://www.sciencedirect. com/science/article/pii/ S0306261911007720 Img_02 source: http://www.flickr.com/ photos/21259491@ N02/2559784889/

http://www.waset.org/ journals/waset/v30/v30101.pdf Analysis on Iranian Wi d Catcher and its effect on Natural Ventilation as a solution towards sustainable architecture, World Academy of Science , Engeneering and technology 30 2009 Analysis of Traditional Iranian Houses of Kashan, Iran in Terms of Space Organization and Access Design Payam Eskandari Eastern Mediterranean University September 2011 GazimaÄ&#x;usa, North Cyprus

1.1 Tower of wind diagram

1.1 Existing Wind Towers in Kashan

AGRICULTURE IN ATACAMA DESERT

MINIMIZE THE TRAVEL DISTANCE BETWEEN AGRICULTURE PRODUC TION AND THE CONSUMERS After the research and observations of the different cities in Atacama desert, regarding the relationship between agriculture and the urban settlements locations. They are typical examples of traditional model of urban configuration where we could distinguish urban settlement from agriculture fields as two different entities. This model use to be convenient for ancient times. Today, the world population growth has lead to cities rapid development and urban sprawl over agriculture fields. These become remote from the city. The land value becomes an important factor inside the city. Therefore, it needs to make profit out of its land by increasing the density. In one hand, the transportation development has shortened the distances. Thus, it is no longer inconvenient to travel long distances to get the food from remote places. On the other hand, it is a tremendous loss of energy and environmental harm. Therefore, it is of our responsibility as architects and planners to react and provide an adequate process of urbanization in contrast with the current urban model. Thus, we aim to design an urban settlement as nearly efficient as possible. The strategy would be to minimize the travel distance for the inhabitants to get their food. We propose an integrated system where agriculture and urban blocks are complementary, addressing the competing demand of land use.

CONCLUSION For that purpose, we were interested into Thunen’s model of the land use, and agriculture optimum location. Following his theory, we defined the convenient range of distances to be the threshold travel for the local population to get food. In our city model, we would place local food production nodes at walk-able distance so that we maximize the efficiency of the system. The vertical farm for instance represent a genuine solution with many advantages that would respond to our targets.

Arica

Iquique

Tocopilla

Calama

Antofagasta

Tal tal

50 km

Chañaral

Caldera

Huasco Alto del carmen

Copiapó

Vallenar

THE VERTICAL FARM

Water fog catchers system

Artificial lightening Plants

Fish tanks Water pumped

Elevator Main pipe to drive water from the fog catchers to the storage point

Market basement

Underground water storage

Concept diagram of our food production towers

IN T ROD U C TI O N Considering the salinisation of the Atacama desert soil, it is no longer possible to practice traditional agriculture. Therefore, it is essential to consider other methods of farming. Vertical farms for instance are a genuine opportunity for us to grow locally the food and reduce the land use. This method represent many benefits socially and environmentally.

A DVA NTAG ES 1. Vertical farming offer a continuous food harvest during the year 2. The weather does not affect the crops production 3. There is no risk of agriculture flooding. 4. The use of Pesticides, herbicides and fertilizers is avoided. 5. Almost 95 % of the water is saved compared with traditional farming. 6. Minimise the travel distance of the consumers to get the food. 7. Better management of the food production in terms of food security and hygiene. According to Dr.Despommier, the author of â&#x20AC;&#x2DC;the Vertical farmâ&#x20AC;&#x2122; (2011), this farming method may integrate Hydroponics, aquaponics in order to maximise the harvest and reduce the crop surfaces in order to reduce the water consumption per person but also allow the recycling of the water.

CONCLU S IO N The system should work as a closed loop with its environment. The water is harvested from the fog in order to produce fruit and vegetables, then recycling water to produce fish that will in turn release bacteria used as a fertiliser to the plants. This harvest will then feed the equivalent population.

AQUAPONIC SYSTEM

PLANTS Bacteria turns fish poop into plant food

The Plants feed the fish

BACTERIA

FISHES

Fish poop feeds the bacteria 1.1 Life cycle loop in Aquaponic system

1.1 Aquaponic System

INT RO D U C TI O N Aquaponics is essentially the combination of Aquaculture and Aeroponic cultivation. More specifically we define aquaculture as farming of fishes and aeroponic as the growing of plants in air environment so without the use of soil. Both aquaculture and aeroponic farming method have some down sides, aereoponic requires expensive nutrients to feed the plants, and also requires periodic flushing of the systems which can lead to waste disposal issues. While re-circulating aquaculture and aeroponics are both very efficient methods of producing fish and vegetables, when we look at the combination of the two, these negative aspects are turned into positives. Research has shown that an aquaponic system uses about 1/10th of the water used to grow vegetables in the ground, so it can be incredibly productive.

ST RAT EGY The plants extract the water and nutrients they need to grow cleaning the water for the fishes by using gravity as a transport. The water is drained from the fish tank into a gravel bed where there are bacteria that live on the surface of the grow bed media. These bacteria convert ammonia wastes from the fish in nitrates that can be used to fertilize the plants. This process take the name of “the nitrogen cycle”. On the gravel bed, we also use watercress as a secondary means of water filtration. The filtered water is pumped from the gravel bed to the growing beds, where we raise a variety of crops. The water is wicked up to the vegetables roots.

FISH ES Many different species of fish can be grown this kind of systems, and your species selection will depend on a number of factors including local regulations. Quite high stocking densities of fish can be grown in an aquaponic system, and because of the recirculating nature of the systems very little water is used. Other aquatic animals that can be incorporated into an aquaponic system are mussles, which are filter-feeder, and so they're able to clean the water, fresh water prawns, and fresh water

crayfish. Crustaceans can also be an addition to an aquaponic system.

PLANTS Research has shown that there are over 300 plants that would grow well in an aquaponics system, depending on location, climate and a variety of other factors. Root plants are definitely worth avoiding, as they’re too sensitive. The best crop though are herbs and green leafy vegetables. We can grow cabbage, cauliflower and broccoli. And with enough care, salad vegetables, Aquaponics systems can in fact easily grow varieties such as lettuce, cucumber, and red onions. Tomatoes are also possible to grown in aeroponic system together with Aubergine, beans and peas.

ADVANTAGES

1. http://www. backyardaquaponics. com/guide-toaquaponics/what-isaquaponics/

1. http://aquaponics.com

http://www. backyardaquaponics. com/Travis/

Aquaponic is a very advantageous systems, the water needed is the 10% of the amount used in traditional agriculture. It allows so the production of fresh food using very little quantity of water and permit the production of fresh food even in most arid places where the resources of water are short. Once established, it requires little effort and time to run the system. Another positivity that has to be taken into account is that no nutrients are waisted in aquaponic and that no chemical fertiliser is used for growing vegetables. Considering the ground conditions of a geographical context as the one of Atacama desert one of the most relevant aspect of this growing system is that the plants don't need to have any contact with the soil. Eventually those raised beds keep plants free also from ground dwelling pests. Aquaponic cultivation contributes so to the conservation of the scarce water resources, it is an environmentally friendly way of growing food and it results really effective in order of costs and energies.

CO NC LUS IO N By combining the aquaponics with the Vertical farm we are significantly reducing the total water consumption. Reducing the water amounts will reduce the surface of nets needed to catch the water that will help in using the fog catchers

WATER COLLECTION METHODS FOGCATCHERS 10 m

Wind

Gutter

NNW

NNE

Drainage system

Site WNW

ENE

Storage system

ESE

WSW

SW SSW

SSE S

Section diagram of the Fog catchers system

L/Sqm/d

Figure:Larg fog collector diagram

30 25 20 15 10 5 0 S -5

N J M M

1997

S N J M M

1998

The collectors are installed perpendicular to prevailing winds.

S N J M M

1999

S N J M M

2000

J S N J M M

2001

J S N J M M

2002

J S N

2003

J M M

J S N

2004

Graph of fog water collections at alto patache_Atacama desert at 850

The graph demonstrate the persistence of the fog phenomenon in the Atacama Desert every year for a period of 6 months. The average water harvested is around 10 liters a day.

FOG H A RVEST

FO G C ATC H ERS INT EGR AT IO N

The fog catchers are big panels of nets, 10 metres large and 4 metres high. They are independent system that collect fog water at high altitudes that is driven to lower level cities.

The fog panels as initially designed, would cover an important surface land area in order to sutisfy the needs of 25 000 people. for instance, if we consider the length of a standard fog panel (10m) and the distancing (4m) required between the fog panels, we would need 40 m2 per panel harvesting 400 litres, which could roughly cover the daily water needs of 1 person. This means that a field of 40 000 m2 will be required to sustain 1000 individuals and 25 times bigger surface to sustain the population target.

The fog is brought by the prevailing wind to the mesh. Tiny water droplets are captured to form bigger droplets that run-down to the gutter by the force of gravity. Then, eventually flow into water tanks or cistern via pipes. For an optimum result the fog nets are recommended to be placed as high as possible from the ground level, typically 2 metres (Schemenauer and Joe (1989) & Schemenauer and Cereceda (1994a,b). Also, The fabric that catches the fog does not absorb water but rather acts as a surface of condensation and the water runs off. Therefore there is no additional structural load that might require advance engineering studies.

T Y P ICA L WATE R H A RV EST The quantity of water harvested from fog depend greatly on the number of fog collectors installed and the rate to harvest in the site, varying daily and seasonally from a site to another. However, the typical harvest estimated by Fogquest organization between 200 and 1000 litres per day. For instance, with 100 LFC (4000 mÂ˛), at El-Tofo, Chile, an average of 15 mÂł per day was produced. The outcome of a square metre of fog catching surface is estimated to be 10 litres per day.

CO NC LUS IO N In this work we would like to consider the fog catcher system as an integral part of the city. The strategy would be to maximise the fog surface and reach the quantity of water needed to sustain 25.000 people for domestic use and food production. Traditional method of agriculture consume a huge amount of water and is considered to be not sustainable solution. Therefore, we would like to explore more efficient methods to minimise the water use and to recycle

Diagram showing the prevailing winds in Atacama desert and positon of the fog catchers. Source:http://www. windfinder.com/ windstats/windstatistic_ desierto_de_atacama

Fog nets on are placed on the hillside to catch the moisture and provide precious water to the village of Bellavista, about 10 miles (16 kilometers) outside of Lima, Peru. Photograph by Anne Lummerich

Domain

Chapter Three

Experiments

CLIMATE IN NORTH OF CHILE

DES E RT CL IM ATE DATA The Atacama desert is the driest area on the Earth, some weather stations, as the Calama one in the central region have never received rain. Although the Tropic of Capricorn passes through the region, the Atacama desert is located in the rain shadow of Chile's Coast Range, which squeezes out the moisture from terrestrial atmosphere. The prevailing winds blows from the east but the tall Andes Mountains prevent that the moisture from the Atlantic Ocean and Amazon basin reaches this area. Atacama is a high, mostly situates over 8000 feet and is classified as cold desert even if the average temperatures range, from 0° to 25° Celsius, is quite mild.

When the wind hit the coastal chain it will then flow sideways or upward. The associates changes in temperature and humidity on the windward side of the mountain often lead to fog while the air on the leeward side is much drier and warmer. Many of the world's deserts lie right a meteorological divide.

C LIM AT E DATA WIND SPEED: 11 mph MAX TEMPERATURE: 26.4 C°

The desert is located on the side of the Chilean Coast Range, where a marine fog known as the Camanchaca from the Pacific Ocean can reach the desert. The Andes and the Coastal chain are high enough to block convective clouds, which could bring precipitation, formed above the Amazon Basin. An inversion layer is created by the cold Humboldt current and the South Pacific High.

MIN TEMPERATURE: 8.3 C° WIND SPEED: 11 mph WIND DIRECTION: North West EVAPORATION RATIO: 3200 mm/year AVERAGE PRECIPITATION: 15 mm/year SOLAR RADIATION: 3800 kWh/sqm DAYLIGHT HOURS: 12 h

4.000 mt

Hot dry winds 1.500 mt Hot humid winds

200 mt

Costal mountain chain

Intermediate depression

Data Source: http://www.weatherand-climate.com/ average-monthly-hoursSunshine,san-pedro-deatacama,Chile Data Source: http://www. climateandweather.com/ weather-in-chile

AVERAGE TEMPERATURE: 18.41 C° RELATIVE HUMIDITY: 18 %

FOE N E FFEC T

Data Source: http://www.contura.rhb. ch/en/edition/201201/ where-weather-systemsclash.html

Andes Foen effect

PERU

Equatorial Current Arid Climate, abundant cloudiness

Arid Cold Climate

Desert Climate

BOLIVIA

Humbolt Current

IQUIQUE

ANTOFAGASTA

Tundra Climate due to altitude, summer precipitation

Semiarid Temperate Climate

CALDERA

with winter rains

COPIAPO

Semiarid Cold Climate ARGENTINA

with winter rains

LA SERENA

Semiarid Climate with abundant cloudiness

SOIL CONDITION IN ATACAMA DESERT

MO RP H OLO G I C A L S C E NA R I O S The region of Atacama is an ensemble of different typologies of landscapes, the desert has rich deposits of copper and other minerals, and the world's largest natural supply of sodium nitrate. There are fiery red canyons, gorges, thermal lakes and geysers. Here, bare volcanoes rise some 20,000 feet. In this variety of possible landscapes three are the most common: FELSIC LAVA, associated with pyroclastic deposits. Most silica lava flows are crinkly peaks and cliffs that seem to burst out of the otherwise flat surface. The combination of abundant craters show how crucial the volcanic activity had been in this area. SAND, the sand dunes landscape is strictly related to the 10.000 years ago Andes volcanic activity. Also the sand is in fact the result of volcanic ash production. SALT LAKES or salt flats are dried-up desert lakes. They form in closed hollows where rainfall canâ&#x20AC;&#x2122;t drain away. The salt and minerals dissolved in the water are left behind as a solid layer.

ATACA M A SA LT L A KE The salt flat encompasses in Atacama Desert is estimated around 3.000 km2, about 100 mt long and 80 mt wide, which makes it the third largest salty region in the world. The Salar de Atacama is the world's largest and purest active source of lithium.

The surface of the Salar de Atacama is churned up and pitted, it exhibits a high level of roughness, resulted by the evaporation and ephemeral surface water. The generator and the actual surroundings of those regions are rivers and volcanoes These characteristics of the desert surface drive our project in favour of cultivation methods which avoid any contact with the soil, too salty to set any agricultural activity.

CO NC LUS IO N From the study of the Climate and soil of Atacama desert, there is evidence that traditional method of agriculture cannot be used anymore in such fragile ecosystem. The water basins are over exploit with no recharge to balance the hydrological system, but also the desertification and the salination of the soil constitute a real threat in the region. One alternative remains in the presence of fog phenomenon that has been experimented for a long time and shown reliable result as source of water. In spite the fact that fog is denser when closer to the coastline, we decided to place our settlement in the inland part of the desert where the situation is more extreme compared with the coastline where other possibilities to bring water could be proposed such as the desalination of sea water.

1.1 Salares of Atacama

Image Source: http://www.exploreatacama.com/eng/ excursions/atacamasaltlake.htm

Coastline

BOLIVIA

Costal mountain chain

ANTOFAGASTA

Atacama Desert

Atacama depression SALARES CALDERA Semiarid Temperate Climate with winter rains

COPIAPO

Andes chain ARGENTINA

Pampa LA SERENA

SITE LOCATION

S I TE S E L EC TI ON

T R ANS PO RT NE T WORK

The selection of the site is a result of a weighted negotiation between fog presence and connectivity, where the presence of the fog is vital for making the city viable but keeping in mind that this is a zone hardly occupied where the connectivity is important as well. In addition, we know that the areas located in the intermediate depression have a highly saline soil, so is logic to avoid to be in flat areas. Finally, the project will be located in the east facing pendant of the coastal mountain chain where there is more connectivity and at the same time there is a high probability of harvest of fog

There are two main roads, the inner main highway and the coastline road. The first one works as a regional and global connective trace and the coastline which is primarily local transport. The site is located between Iquique in north and Calama in the south.

FO G P E NE TR AT IO N CO R R IDO R The continuous fog existing in the coast of Atacama desert usually is not able to pass the coastal mountain chain in large parts of the coastline. But there are some exceptions where the moist air is able to penetrate inland through corridors, which in this case is the Loa river valley.

located in wide flats or depressions. This kind of soil are quite inhospitable as well as non cultivable because of the minerals within it.

CO NC LUS IO N In order to choose the specific site, it is crucial to run wind analysis so that we can insure the good function of the fog catchers in the site so that we maximise the water fog harvest.

SA LT F L ATS 1.1 Location of the corridor along river Loa and between both existing main roads.

The existence of salt flats is due to ancient salt lakes that have being getting dry and they are located in wide flats or depressions. This kind of soil are quite inhospitable as well as non cultivable because of the minerals within it.

1.1

1.1 Satellite image representing the fog corridor 1.1 Location 5 Km

1.1 Connectivity and Fog Penetration

CO NC LUS IO N

6.168 Pica

Pozo Almonte

Iquique

km 23 km

78 74

Being in the corridor will significantly reduce the fog (25% less)but will still harvest an amount of 7.5 litres per square metre per day. The settlement is located at 17 km from the main network that crosses the country from the south up to the north. It is also at mid way from important settlements at a maximum distance of 200 km.

10.830

221.000

km 00

1.1 5 x 5 km topographic plan

25.000

6.168 Pica

Tocopilla

Pozo Almonte

143.000

Main network south-north

Maria Elena

Pozo Almonte

Iquique

7.530

221.000

1.1 Digital model of the corridor

km 23 km

23.986

km 00

Iquique

10.830

Site

Calama

4.696

25.000

San Pedro de Atacama

Tocopilla Calama

23.986 Tocopilla

7.530

Maria Elena

143.000 Calama

7.5 L

4.696 San Pedro de Atacama

15 L

1.1

WIND ANALYSIS: SITE

1.1 In plan view the analysis shows how the small hills make the velocity decrease

6 m/s

1.1 Plan view 1.1 By blocking the wind, the hills make the wind to go higher

1.1 Section 1

1.1 Section 2

1.1 Section 3

Water Convergence

1 m/s

SIT E CFD We selected the site relying in a topographic characteristic within the Fog Penetration Corridor where two small hills form an interstitial depression or valley among them where the wind might accelerate in order to maximize the capabilities of the fog to be cached.

The next step would be to look at the behaviour of various building shape when exposed to wind. this will inform us about the optimum shape to respond to the fog catching system but also at the relationship between buildings so that each one will allow the penetration of fog to the next one for a optimum fog water harvest.

1. Cereceda, H. Larrain, P. Osses, P. Lázaro, R. Pinto & R.S. Schemenauer)

SE T U P We made the wind flow inlet coming from the south west as it happens on the site, keeping in mind that there will be an angular variation range of roughly 30 degrees on the wind direction. We performed the analysis simulating a 5 m/s wind velocity which is the average speed in this area.

RESU LTS After we made the CFD we saw that the predicted behaviour was somehow right, where the wind maybe didn’t accelerate as much as we expected at ground condition, but still the velocity wasn’t decreasing, making it a perfect scenario for the water to be harvested from the fog.

CONCLU S IO N Keeping this in mind we got as a result that even when the wind was decelerating after the hills, that was just happening at ground condition and a range of meters above, meaning that in the case of trying to collect fog from these areas we would need to allocate de “fog catchers” higher than in the rest of the more suitable area (the valley) were we could place them just in the altitude stated on the previous referenced experiments1. We realize also that the characteristics of the fog change depending on the altitude according to different temperatures and existing pressures.

Experiments

WIND SHADOW

1.1 Plan views of CFD Analyses showing generated wind shadows due to different geometries

24m

1.1 Square footprint

24m

6 m/s

6m 1.1 Circular footprint

1 m/s

26m

6m 1.1 Concave footprint 1.1 Different heights don't mean variable wind shadows, but a different wind behavior within the wind shadow

26m 1.1 Extrusion: 5 mt

5.5m 1.1 Star footprint

Water Convergence

1.1 Extrusion: 10 mt

P RIM IT IVES C F D

CO NC LUS IO N

After having a basic understanding on how the wind was behaving in the site we wanted to analyse what would be the behaviour of the wind when hitting different geometric volumes or primitives in a real scale to see whether a geometry was more reliable of collecting more fog than others.

What basically the experiments provide us is the information about the distance of the wind shadow area where a volume would be affecting another in terms of wind exposure.

SE T U P Primitives of a similar diameter: two of convex profile and two concave were placed in a simulation box in the exact same location. Their height was 5 mt simulating a building real scale. The wind velocity was set at 5 m/s, the same used for the previous experiment, but this time, the real direction was given(south-west). Just one of the geometries was analysed with 10 mt height as well.

RESU LTS There was a considerable difference in the local behaviour of concave geometries, especially the third, making more global turbulence within the simulation bounding box.

Before going further into the buildings and the design, we must investigate the water needed per person for both domestic and agricultural use and then translate it into fog catchers surface.

These results give us a hint on what kind of geometries we should work with when starting to design at the building scale. The more significant conclusion was that regardless of the primitive to be analysed the â&#x20AC;&#x153;wind shadowâ&#x20AC;?, meaning the space where the wind modifies its direction and velocity behind the element blocking the wind, producing a space of turbulence, was always defined with an equation of y=5x,"x" being the diameter and "y" being the wind shadow lenght. This experiment analysed just strait extrusions without considering tilted walls where the ratio of the wind shadow should definitively change, especially when analysing the section of the fluid dynamics around the primitive. In addition, this analyses where looking for wind behaviour around solid objects without taking into account porous objects like meshes in order to allow the wind to trespass the net and be able of take the moisture of, in this case, the fog without blocking the continuity of the wind flow.

WIND SURFACE BEHAVIOR

PR IM IT IV ES C F D After having a basic understanding on how the wind was behaving in the site we wanted to analyse what would be the behaviour of the wind when hitting different geometric volumes or primitives in a real scale to see whether a geometry was more reliable of collecting more fog than others.

S E T UP

1.1 Symmetrical Concave surface

6 m/s

Primitives of a similar diameter: two of convex profile and two concave were placed in a simulation box in the exact same location. Their height was 5 mt simulating a building real scale. The wind velocity was set at 5 m/s, the same used for the previous experiment, but this time, the real direction was given(west - south). Just one of the geometries was analysed with 10 mt height as well.

R ES ULTS 1.1 Asymmetrical Concave surface

1.1 Symmetrical Convex surface

1.1 Asymmetrical Convex surface

1 m/s

There was a considerable difference in the local behaviour of concave geometries, specially the third, making more global turbulence within the simulation bounding box. These results give us a hint on what kind of geometries we should work with when starting to design at the building scale. The more significant conclusion was that regardless of the primitive to be analysed the â&#x20AC;&#x153;wind shadowâ&#x20AC;?, meaning the space where the wind modifies its direction and velocity behind the element blocking the wind, producing a space of turbulence, was always defined with an equation of y=5x,"x" being the diameter and "y" being the wind shadow lenght. This experiment analysed just strait extrusions without considering tilted walls where the ratio of the wind shadow should definitively change, especially when analysing the section of the fluid dynamics around the primitive. In addition, this analyses where looking for wind behaviour around solid objects without taking into account porous objects like meshes in order to allow the wind to trespass the net and be able of take the moisture of, in this case, the fog without blocking the continuity of the wind flow.

WIND SURFACE BEHAVIOR CO NC LUS IO N What basically the experiments provide us is the information about the distance of the wind shadow area where a volume would be affecting another in terms of wind exposure.

1.1 Double Concave surface distancing= 4m

But as a conclusion to these analyses we know that beside having a wind shadow ratio for strait geometries when changing the inclination of the walls we can drive winds flowing over the terrain to higher levels to maximize the harvest of water from fog. This can be easily seen when analysing the sections, to know that the velocity of the wind is much higher while you see the velocity up into the space surrounding the geometry. Before going further into the buildings and the design, we must investigate the water needed per person for both domestic and agricultural use and then translate it into fog catchers surface.

1.1 Double Concave surface distancing= 8m

1.1 Double Concave surface distancing= 12m

S E T UP

1.1 Surface distancing= 10m

6 m/s

Primitives of a similar diameter: two of convex profile and two concave were placed in a simulation box in the exact same location. Their height was 5 mt simulating a building real scale. The wind velocity was set it at 5 m/s, the same used for the previous experiment, but this time, the real direction was given(west - south). Just one of the geometries was analysed with 10 mt height as well.

R ES ULTS 1.1 Surface distancing= 20m

1.1 Surface distancing= 15m

1 m/s

CO NC LUS IO N What basically the experiments provide us is the information about the distance of the wind shadow area where a volume would be affecting another in terms of wind exposure. But as a conclusion to these analyses we know that beside having a wind shadow ratio for strait geometries when changing the inclination of the walls we can drive winds flowing over the terrain to higher levels to maximize the harvest of water from fog. This can be easily seen when analysing the sections, to know that the velocity of the wind is much higher while you see the velocity up into the space surrounding the geometry. Before going further into the buildings and the design, we must investigate the water needed per person for both domestic and agricultural use and then translate it into fog catchers surface.

WATER CONSUMPTION

DAILY TOTAL WATER CONSUMPTION 65% 35%

Ratio=1.85

228 Litres

DAILY AGRICULTURAL USE

148

Litres

0.148 m続

Consume almost double (1.85) the amount of domestic water

DAILY DOMESTIC USE

80 Litres 0.08 m続

YEARLY AGRICULTURAL USE

54.02

m続

YEARLY DOMESTIC USE

29.2

m続

In order to project a settlement for 25,000 people, we had to fully understand the quantity of water necessary for domestic use and irrigation. This would also help us to quantify the overall water collection and storage required for the settlement.

D OM EST IC NE E DS P E R P E RS O N Considering the local consumption in Atacama Desert. We were surprised that the consumption reaches 120 litres a day per inhabitant in spite of the scarcity of water in the region. On the other hand, the UN water estimation suggests that the daily water needed per person is 20-50 litres to ensure the basic needs in terms of drinking, cooking and cleaning. Therefore, we decided to reduce to half the current consumption by ensuring the 50 litres suggested by the UN, plus an extra 30 litres that half of it (16 litres) will cover the 20% of water losses. Hence, we genuinely believe that an amount of 54 litres might be able to secure ample the needs of one person.

IRRIGAT ION NE E DS P E R C A P I TA After comparing the amount of water required to irrigate the crops between different methods of agriculture, we found that the conventional method were using 17.66 m³ per 100 m² to feed one person, which is almost seven times the amount of water needed for a vertical farm 2.64 m³ to irrigate the surface of 10 m² proved to be sufficient to sustain a single person using this method. Parallel to that, we considered the water consumed to irrigate the agricultural land of Anfogasta in Atacama Desert, which is based on conventional method of cultivation and represent 73% of the overall water consumption. From that, we reduce this consumption to its equivalent when using vertical farming, roughly 20% less water intake. The result gave us an amount of 0.148 m³ per 10 m² per person.

TOTAL WAT ER CO NS UMPT IO N EST IMAT IO NS The calculation of water consumption were estimated per person during a day time. The total amount is a combination of water needed for daily domestic use (drinking, cooking and cleaning), and water needed for daily food production in a vertical farm system (irrigation of fruits and vegetables). However, the daily water amount for irrigation 65% seems to be exceeding the water for daily domestic use 35% that represent a ratio of 1.85 which is almost the double.

1. Source: World Water Assessment Programme (WWAP) http://www. unwater.org/ statistics_san.html

2. Source:

CO NC LUS IO N To summarise, regarding the environment of the Atacama Desert, our objectives in this work are an attempt to minimise the water losses and consumption by using the most efficient approaches and encourage people to reduce as much as possible their water use. Thus, we genuinely believe that decreasing both domestic and irrigation water use may have a great impact on the local environment but also on the global ecosystem and secure the future for all living things. Specifically to our project, reducing the total water needs will reduce drastically the fog catchers surface which facilitate the feasibility of the system. Knowing the amounts of water needed for one person, The next step will be to translate these amounts of water into surfaces of fog catchers needed for a single person.

Method

FOG CATCHERS SYSTEM INTEGRATION H O US ES We also aiming to integrate the fog catchers in the houses in order to provide the daily water needs for the householders in terms of drinking, cooking and cleaning. As earlier mentioned, 80 litres would cover the total needs per person. Therefore, one household unit containing 2.59 people will need:

hers ed in the

Fog catchers (nets)

STIC USE

80L* 2.59 = 207.2 litres per household.

House unit

Litres

Fog surface= 10.66 m²

Litres

Fog surface= 10.66 m²

The equivalent surface to catch this water would be equal to: 207.2 L * 1 m2/ 7.5 L = 27.62 m2

ed for dry season

21.32 m²

Undergound water storage

By breaking-down the total amount surface to a single person needs we would have 10.66 m2 of fog catchers to sustain the daily needs of one person to drink, cook and clean. In the same way as in the towers, it is essential to take in account the dry season when the fog is absent during the half of the year. Therefore, we will need to double the harvest to secure the needs in the dry season.

est need to be doubled during the wet the half of harvest for the dry period.

est per day= 160 Litres per Day/ person. DIAGRAMATIC CONCEPT OF THE HOUSE

Thus, the fog catchers surface need to be doubled to 21.32 m2 per person. The surplus is also driven to water tanks placed underground in order to minimise the water evaporation. Fog catchers integrated in the vetrical farm

DAILY AGRICULTURAL USE

148 Litres

Fog catchers (nets)

Fog surface= 19.73 m²

Farming layers

148 Litres

Fog surface= 19.73 m² Stored for dry season

296 Litres

39.46 m²

Tower base (Farming) Undergound water storage

*Daily water harvest need to be doubled during the wet season and store the half of harvest for the dry period. Total water harvest per day= 296 DIAGRAMATIC CONCEPT OF THE VERTICAL FARM INTEGRATING THE FOG NETS

FOO D P RODU C TI O N TOW E RS In order to maximise the water catchment and Fog catchers integrated in the optimise the land use we intent to merge the nets in vetrical farm the towers as well as the houses in order to produce DAILY locally the water needs. AGRICULTURAL USE Firstly, by integrating the fog catchers in the towers 148 Litres Fog surface= 19.73 m² we will maximise the nets in order to achieve the water needed to irrigate the plants. 148 Litres

Fog catchers (nets)

Farming layers

Fog surface= 19.73 m²

for dry seasontower Our intent is to design a food Stored production to sustain 1000 people. Following the water consumption per person calculated we will 296 Litres earlier, 39.46 m² have to allot 10 m2 to grow its food what will imply 148 daily irrigation. This mean that we would need a total amount of: *Daily water harvest need to be

Tower base (Farming) Undergound water storage

doubled during the wet season and

148L * 1000 = 148 000 litres (148 m3) per tower. store the half of harvest for the dry period.

The equivalent surface to catch this water would be equal to: Total water harvest per day= 296 148 000L * 1 m2 / 7.5L= 19 733 m2 By breaking-down the total amount surface to a single person needs we would have 19.73 m2 of fog catchers to sustain their daily needs in terms of food. However, is essential to take in account the dry season when the fog is absent during the half of the year. Therefore, we will need to double the harvest at the foggy season to secure the water needs in the dry season . Thus, the fog catchers surface need to be doubled to 39.46 m2 per person. The surplus of water harvested per day will be stored in underground water to avoid the evaporation process due too high solar radiation in the region.

DIAGRAMATIC CONCEPT OF THE VERTICAL FARM INTEGRATING THE FOG NETS

Fog catchers integrated in the house

Fog catchers (nets)

DAILY DOMESTIC USE

House unit

80 Litres

Fog surface= 10.66 m²

80 Litres

Fog surface= 10.66 m²

Stored for dry season

160 Litres

21.32 m²

Undergound water storage

CONCLU S IO N After calculating the amount of fog catchers surface in the food production towers and the houses. One can observe that the surface needed to produce water for irrigation is considerably high compared with the surface needed to catch water in the houses. Therefore, we may need to investigate other strategies to reduce this surface catchment in the towers.

However, Daily water harvest need to be doubled during the wet season and store the half of harvest for the dry period.

Total water harvest per day= 160 Litres per Day/ person. DIAGRAMATIC CONCEPT OF HOUSE

IN T RO DUC T IO N After estimating the fog catchers surface that correspond to the water needs per person, we can observe that higher amounts of fog catchers surface are needed for agriculture irrigation. This has led us to thing about other alternatives to distribute the nets and be able to catch large amounts of water.

FAR MING TOW E RS 1.1 Total Surface: 8.024 m2 Amount of People able to feed: 803 Water Needed: 21.663 m3

The Farming Towers are conceptualized as exclusive food production towers of several stories, where the facade is capable of collecting water according to the fog harvest method previously mentioned. This way the towers can provide themselves of enough water to produce the food. At the same time the overall floor surface in all the stories is going to give us the amount of water needed for the planted surface as well as the amount of people able to be fed.

Agriculture surface

Storage Tank

S E T UP We created an algebraic definition in Grasshopper capable of calculate both the global planted surface area and the fog collection nets in order to know what is the difference between the amount of water needed and the amount of water actually being harvested. 1.1

1.1 Diagram showing the body plan of the farming tower where there would be a side catching the fog while the other side would be dealing with the sun exposure mainly.

Prevailing wind

In the opposite page the surface for both the fog collection surface and the volume of water to be stores are compared and the calculation give us the the deficit in this case of each one.

Food production tower 1.1

R ES ULTS

WATER COLLECTION & STORAGE RATIO

FARM ING TOWE RS The Farming Towers are conceptualized as exclusive food production towers of several stories, where the facade is capable of collecting water according to the fog harvest method previously mentioned. This way the towers can provide themselves of enough water to produce the food. At the same time the overall floor surface in all the stories is going to give us the amount of water needed for the planted surface as well as the amount of people able to be fed.

Fog catcher surface: 1.256 m2 Water Collected: 1.715 m3

SE T U P We created an algebraic definition in Grasshopper that calculate both the global planted surface area and the fog collection nets in order to know what is the difference between the amount of water needed and the amount of water actually being harvested.

Catching Net

RESU LTS 1.1

The real harvest, just using the halve of the facade which is facing the wind, is just 12,6% of what the tower actually needs. At the same time, the tank needed for storing the amount of water needed is too big and not proportional to the building. In the opposite page the surface for both the fog collection surface and the volume of water to be stores are compared and the calculation give us the the deficit in this case of each one.

CONCLU S IO N

Fog catcher area Deficit: - 14.619 m2 Water Deficit: - 19.948 m3

The amount of surface needed to provide enough water for the tower to be able to grow food properly is considerably higher than actual size of the tower. Therefore, it is imperative to find a way of optimizing the catchment surface as well as looking for a collaboration coming from the buildings that would be surrounding the Farming Towers.

1.1

EXPERIMENTS: GEOMETRY OPTIMIZATION - FCSA / PSA ratio: 0.70 - Prod. for 32 people

- FCSA / PSA ratio: 0.70 - Prod. for 63 people

- FCSA / PSA ratio: 0.50 - Prod. for 40 people

- FCSA / PSA ratio: 0.50 - Prod. for 79 people

- FCSA / PSA ratio: 0.50 - Prod. for 62 people

- FCSA / PSA ratio: 0.50 - Prod. for 71 people

- FCSA / PSA ratio: 0.50 - Prod. for 79 people

- FCSA / PSA ratio: 0.45 - Prod. for 78 people

- FCSA / PSA ratio: 0.50 - Prod. for 55 people

1.1 First Tower Optimization 1.1 H. Larrain, 2009, http://ecoantropologia.blogspot. co.uk/2009_01_01_ archive.html

GEOM E T RY C HA NG E

R ES ULTS

According to the results of the previous experiment about food production tower, we had to increase the amount of water collection surface. In this second attempt we look for an geometrical optimization to look for a fitter tower in terms of water catchment, storage and feeding capacity.

The fittest tower gave us a 0.7 ratio and most of the alternatives of the later generations gave us around a 0.5 ratio. This mean that the FCSA meets or gives a surplus on the demand of water for the tower to produce food required for the target population but still not year-round requirements.

SE T U P

CO NC LUS IO N

The net skin which collect the fog is now able to take some distance from the production building itself with an offset parameter, this way the fog collection surface area (FCSA) is maximized.

Although the fittest tower would be able to harvest 70% of the water needed, the amount of people that it can feed is too low which is not efficient nor feasible according to the vertical farm standards1 . This may result in 781 towers to feed the whole population target.

The parameters used were: - The amount of sides that the profile geometry of the FCS has,

1. Dickson Despommier, 2010, The Vertical Farm.

- The offset distance of the FCS on a range of 0-5 mt, - The offset of the outer sides of the profile geometry in a range of 0-5 mt, - Footprint radius of the production tower in a range of 4-13, - Number of stories. The fitness criteria was the needed fog collection surface area (FCSA) over the food production surface area (PSA) looking for a ratio as closer to 1.0 as possible in order to meet the demand of water so that the tower reach the target feeding capacity including the dry season.

EXPERIMENTS: DIMENSIONAL OPTIMIZATION - FCSA / PSA ratio: 0.23 - Prod. for 319 people

- FCSA / PSA ratio: 0.12 - Prod. for 425 people

- FCSA / PSA ratio: 0.14 - Prod. for 319 people

- FCSA / PSA ratio: 0.13 - Prod. for 372 people

- FCSA / PSA ratio: 0.13 - Prod. for 425 people

- FCSA / PSA ratio: 0.26 - Prod. for 478 people

- FCSA / PSA ratio: 0.26 - Prod. for 372 people

- FCSA / PSA ratio: 0.24 - Prod. for 425 people

1.1 Second Tower Optimization

FCSA: Fog Catching Surface Area PSA: Production Surface Area

D IM E NSIO N R A NG ES After the previous experiment we want to maximize further the water collection surface looking for a higher harvest to meet the demand of the single tower and increasing the feeding capacity according to the PSA.

SE T U P The same set up used in the previous experiment but restricting the footprint area and we ensure a higher amount of people to be fed. The parameters used were: - The amount of sides that the profile geometry of the FCS has, - The offset distance of the FCS on a range of 0-5 mt, - The offset of the outer sides of the profile geometry in a range of 0-5 mt, - Footprint radius of the production tower in a range of 8-12 - Amount of stories. The fitness criteria again was FCSA / PSA seeking to maximize the ratio as much as possible in the ranges stated before.

RESU LTS A considerable maximization of production area was achieved being able to feed up to 478 people but on the other hand the FCSA / PSA ratio decrease when constricting the offset distance of FCS to 5 mt.

CONCLU S IO N Although the FCS was maximized, it wasn't enough to feed the target amount of people set to 1000. The increase of area has to be related to the growth of the FCS exponentially. As a next step, we must investigate other strategies to maximise the feeding capacity but also maximise the water harvest to achieve 1000 people feeding capacity per tower.

EXPERIMENTS: TOWERS ARRANGEMENT - FCSA / PSA ratio: 0.44 - Prod. for 272 people

- FCSA / PSA ratio: 0.17 - Prod. for 662 people

- FCSA / PSA ratio: 0.13 - Prod. for 475 people

- FCSA / PSA ratio: 0.32 - Prod. for 362 people

- FCSA / PSA ratio: 0.14 - Prod. for 686 people

- FCSA / PSA ratio: 0.12 - Prod. for 589 people

- FCSA / PSA ratio: 0.26 - Prod. for 453 people

- FCSA / PSA ratio: 0.12 - Prod. for 754 people

- FCSA / PSA ratio: 0.11 - Prod. for 980 people

D IM E NSIO N We proceed further with the experiment in order to achieve the target population and meet the water demand. We look at a new strategy of splitting the single tower what will probably increase the production surface area but also the fog catching surface between the towers.

SE T U P With the same parameters set in the previous experiments but this time we split the tower into 2, 3, 4 and 5 footprints which will maximise the fog catching surface area.

RESU LTS Running an evolutionary algorithm giving a much higher FCSA/PSA ratio but this is again lowering the feeding capacity of the tower.

CONCLU S IO N Splitting the tower into 3 entities was enhancing the ratio of FCSA/PSA equal to 0.17. However, the feeding capacity was still not yet achieved. Therefore, we decided to look at alternative strategies to achieve our purpose. For instance, make a collaboration system between the towers and the residential buildings to meet the water demand to grow the food.

STORAGE ARRANGEMENT

STO RAGE ST R ATEG I ES

R ES ULTS

The amount water that has to be collected in order to make the vertical farms to work autonomously is drastically higher than the amount needed for domestic use. The same way, the water needed to be stored for the dry period when there is no fog is also high. Therefore we looked for a strategy to store the water so that we avoid having huge tanks getting out of scale. We think the most efficient way would be to create a collaborative system where residential and agricultural collection and storage happens, specially looking at how much a tower needs and how much can it actually collect. This is how the big difference on water needs can be sort it out.

This helped us to visualize the size that the amount of water needed would be like. We know as a result of this experiment that the storage system should be integrated and collaborative so the volumes of water can be more manageable.

SET U P The images on the left shows the relation between two different collaborative scenarios. In the first one there the overall water needs (Agriculture & Residential) is being equally distributed between the Agricultural Node and 9 block size hubs (10 tanks). The second is storing 65% of the overall water needs in the Agricultural Node and the other 35% equally distributed in 9 block size hubs. All of them showing tank proportions for year round, including the dry season.

CO NC LUS IO N The amount of water that the tower is able to collect is far behind from what it actually needs to grow all the food. Therefore, it is essential to find a strategy of maximizing the fog catching surface to achieve the required amount. Thus, we propose to incorporate additional fog catchers in the residential buildings so that each block unit (a cluster of houses) will produce surplus water to meet both demand of water of the inhabitants and the deficit of the tower. This will probably result in a more collaborative system between the residential and the agriculture production.

1.1 Proportional 4m

Agriculture: 31.288 m3 (65%) Residential: 1.879 m3 each hub (35%)

1.1 Balanced & Collaborative 4m Agriculture:

4.820 m3

Residential: 4.820 m3 each hub

100

Water Convergence

1. Diagrammatic approaches of water collection and distribution between farming towers and residential buildings.

WATER COLLECTION AND DISTRIBUTION

WAT E R DIST R IB UT IO N ST R AT EGY The estimations of total water needs suggest that the water amounts for agriculture is much higher compared with the amount of water necessary for domestic use. Therefore, we suggest an alternative strategy to cover the deficit of water to irrigate the crops by maximising the surface catchment in the residential building. Each housing block will maximise the water fog catchment and have a collective water storage that will feed the towers. Considering the topography of the site we would like to make this system work passively by placing the towers at lower level so that the housing blocks will always be higher which will facilitate the water flow and minimise additional energy consumption to drive the water.

CO NC LUS IO N In order to proceed further, we will set an experiment looking for 25 lowest points in the site. In this points will emerge the food production towers.

Underground water storage receiving water from the tower nets and the housing blocks storage tanks to meet the demand of agriculture

101

HOUSING TYPOLOGIES

Individual Individual househouse unit unit

Street/terrace Street/terrace

& C block U & CUblock

of storeys: 1 storey Num.Num. of storeys: 1 storey Num. of units= 36 Num. of units= 36 Built ratio= Built ratio= 100%100% Unbuilt Unbuilt ratio=ratio= 0% 0%

of storeys: 1&2 storeys Num.Num. of storeys: 1&2 storeys Num. of units= 36 Num. of units= 36 Built ratio= Built ratio= 55.5655.56 % % Unbuilt ratio= Unbuilt ratio= 44.4444.44 % %

of storeys: 2 storeys Num.Num. of storeys: 2 storeys Num. of units= 36 Num. of units= 36 Built ratio= 78.76% Built ratio= 78.76% Unbuilt ratio= 221.24% Unbuilt ratio= 221.24%

of storeys: & 2 storeys Num.Num. of storeys: 1 & 21storeys of units= Num.Num. of units= 36 36 Built ratio= 52.75% Built ratio= 52.75% Unbuilt 47.25% Unbuilt ratio=ratio= 47.25%

of storeys: 1&2 storeys Num.Num. of storeys: 1&2 storeys Built ratio= 58.83% Built ratio= 58.83% Unbuilt 41.17% Unbuilt ratio=ratio= 41.17%

of storeys= 4 storeys Num.Num. of storeys= 4 storeys of units= Num.Num. of units= 36 36 Built ratio= Built ratio= 53% 53% Unbuilt Unbuilt ratio=ratio= 47% 47%

of storeys: 4 storeys Num.Num. of storeys: 4 storeys of units= Num.Num. of units= 36 36 Built ratio= 62.75% Built ratio= 62.75% Unbuilt 37.25% Unbuilt ratio=ratio= 37.25%

of storeys: 1&2 storeys Num.Num. of storeys: 1&2 storeys of units= Num.Num. of units= 36 36 Built ratio= Built ratio= 75% 75% Unbuilt Unbuilt ratio=ratio= 25% 25%

of storeys= 5 storeys Num.Num. of storeys= 5 storeys of units= Num.Num. of units= 36 36 Built ratio= 41.18% Built ratio= 41.18% Unbuilt 58.82% Unbuilt ratio=ratio= 58.82%

Courtyard Courtyard blocksblocks

102

103

1. First Food Production Tower

Highest point= First Food Production Tower

2. Generation rule for the further Food Production Towers = R2

800 m

= R1

400 m

R2 =

0m 80

R1 00 m =4

Food Production Towers Area covered by the wind shadow 400 m Radius of walkable distance

Points generation based on 800 mt radius distance and by the selection of the individual with the highest Y value.

104

First Food Production Tower

Stream ďŹ&#x201A;ow

Food Production Towers

800 mt radius of double walkable distance

Water Convergence

EXPERIMENT 06 FROM THE HIGHEST POINT IN T ROD U C TI O N

R ES ULTS

To start growing our system we looked to how to generate the Food Production Towers in order to allow a water distribution able to take the advantage of the gravity. The position of those objects represents, in this stage of the project, the starting points to then generate the further subdivisions and connections of our urban settlement.

The results of this test is a set of points homogeneously distributed on the site surface according to its morphology and the rules. What the result is representing for the development of the project is the observation of the growth of the system. The aim remain to test the logic behind the water distribution between houses and Food Production Towers. Is truly this aspect to push us to experiment a different logic more efficient for our needs.

1. B. McGRATH â&#x20AC;&#x2DC;Digital Modelling for urban designâ&#x20AC;&#x2122; John Wiley and Sons publication

SE T U P The generation of the points on the surface begin with the determination of a first highest individual. The logic will lead to the evaluation of the morphology of the site to place the Food Production Towers that distributes the water to the lower residential areas tanks without the use of pumps. The first generation of individuals grow considering the highest point on it a 400 mt radius circumference. Those variables are associated with the calculation of the farest point from the average node of the water streams. Those last were generated in a circular shape with 10 points centered on the food production nodes. From those cercles the grasshopper plug-in water flow allow the simulation of the water flow. The 400 mt value is determined according to an easable walking distance which allows all the inhabitants of the site to quickly reach the closest Food Production Tower to cater nutriments. In order to avoid the reiteration of the same points in the same region of the previous ones generated, fact that happens for the nature of the patch which has a descendent morphology, we forced the system to advance in the X axis. This first experiment will lead to an ordinate distribution of points in the site morphology selected among the others by decreasing Y value, distance from the water flow and the 400 mt circumference.

CO NC LUS IO N The result we get followed the premises and confirmed our expectations. But the logic of the system prooved to have some lack when we considered the amount of water we need to store to supply the urban settlement even in the dry season. The seasonality of the fog forces to store considerable amount of water in tanks that grows esponentially. The calculation of the proper volume needed to provide the Food Production Towers drives our research to reverse the logic system the possibility to collect water from the single dwellings become so a much more achievable hypothesis. This will allow a subdivision of the tanks storage volume and a no pump water distribution. In this stage the weakness of the idea to drive the water from the Food Production Towers to the residential areas became tangible, so the next step will be to test the opposite strategy.

105

1. 400 mt Grid points arrangement

2. The water flow generates the Food Production Towers

Food production node Area covered by the wind shadow 400 m grid dimension (walkable distance)

The Food Production Towers generated is based on the average of the connection points of the streams in a region delimited by 400 * 400 grid . Each region cannot include more than one FPT.

Food production towers

106

Stream ďŹ&#x201A;ow

EXPERIMENT 06 FROM THE LOWEST POINT ACCORDING WITH WATER FLOW IN T RO D U C TI O N

R ES ULTS

In this test we try to refine the technique that will allow us to place the Food Production Towers in the lowest areas of the most windy patch of our site. The logic is reverse in relation to the last experiment and uses the water flow differently. The aim is to have a more organic distribution of points, reason why we generate this time the points according to streams flow which, running according to the topography of the site provides data related to the intersection of the streams. Another achievement is the observation of the growth of the system from the lowest point.

The obtained configuration of the system satisfies our expectations. The use of the grid was probably not the best to out space the Food Production Towers, some of them in fact end up anyway being too close each others. But the main reason why we didn't proceed with this configuration is the logic at its base. The idea of using the water flow revealed us the characteristics of the morphology and allowed us to easily identify the lowest point. But at the same time the process run exclusively superficially and for the pipe diameter needed this is not possible.

SET UP

CO NC LUS IO N

The experiment begin with the generation of the first point. This starting point is the lowest of the topography and has been calculating sorting the list according to the Y axis. This statement is set according to the logic of distributing the Food Production Towers where they are able to receive the water collected by the fog catchers of the habitations. The further individuals are generated following the number of intersections of the streams flow which are naturally the lowest areas in the patch. Evaluating them we determined the next point according to the average height in the cell.

This experiment open our research to some reflections about the transportation of the water more than its distribution, which was the real reason we run this test. The results and their logic evaluation helped us to direct the next experiment considering the position of the points solely according to the Y axis position and eliminating the water flow parameter that would help us only in case of overground water distribution, which is in this site not praticable.

1. Frei OTTO â&#x20AC;&#x2DC;Occupying and connectingâ&#x20AC;&#x2122; Axel Menges Edition

The points where the biggest number of streams were intersecting has been firstly detected. The second operation is to furnish a range in which the system can select its component in order not to have too close Food Production Towers. This is tested applying a grid to the surface. The cells of the grid can contain only one point each. The reason why those towers can not coexist in the same region is the wind shadow that can affect the fog collection of the closest other centres. The dimension of the cell is set according to a reasonable walking distance.

107

1. First food production tower -Lowest point-

Lowest point, First Food Production Tower

2. Second food production tower = R1

400 m

R1 00 m =4 First Food Production Tower Food production nodes Area covered by the wind shadow 400 m radius walkable distance

Food production towers generation based on maximum 800 m distance between the towers and their value on the Y axis.

108

First Food Production Tower

Generation order

Food Production Towers

Half walkable distance

EXPERIMENT 07 FROM THE LOWEST POINT IN T ROD U C TI O N

R ES ULTS

This exercise is the last one that will be done to detect the position of the Food Production Centres. It tests the water distribution from the residential areas, placed in the highest points of the site, to the Food Production Centres. In this case the development follows a similar logic of the previous test, aiming both to select the lowest points on the surface. The goal is to maximize the collection of water of the dwellings and to drive it to the towers in order to easily satisfying the hydrological requirements of the agricultural system through all the year and without the usage of pumps.

The achievement of this test is to obtain a set of points following the morphology of the site and developing according to the growth of value in the Y axis. What we observe in relation to this disposition of elements is that it proves to be the better solution in relation to the other trial. The qualities we are evaluates as considerable improvements are first of all the new logic able to drive the system than the simplification of the entire process. This reduction of rules is mainly obtained eliminating the topography factor and the water drainage system that were adding a non required level of complexity to the system.

SE T U P The process of placing the Food Production Towers which begins from the lowest possible point of the surface has being simplified and rationalised. This abstraction of the further tests helped us to evaluate another configuration of food Production Centres. After having determined the position of the first one, following a radius of 200 mt the algorithm selects the lowest point in the Y axis in that circumference. The numeric value is expression of the half of the walking distance taken into account until now. This rehash of that dimensions has been calculate in order to obtain a bigger number of Food Production Centres and more accurately to obtain a path from centre to centre of 400 mt (sum of the two 200 mt radius). In order not to have a sequence of same points and so to avoid the back and forward effect specifically happening for the morphology of the chosen patch, we set a rule that forces the evolution of the points by having an always decreasing X value. This rule emerges from the evaluation of the downwards topography of the surface from the lowest point. The result of this operation is the creation of a longitudinal development of points in an always Y axis decreasing position

B. McGrath â&#x20AC;&#x2DC;Digital Modelling for urban designâ&#x20AC;&#x2122; John Wiley and Sons publication

CO NC LUS IO N The resulting data of this system that proceeds reiterating the strategy of selecting the lowest point. Each step demonstrates to be efficient both for our entire water distribution system and for a homogeneous configuration of the Food Production Centres. Those factors direct our research to the use of this strategy as the last configuration. Having the lowest points (food production nodes) in the site respecting a distance criteria (walk-able distance) between these production nodes will help us in converging water from the housing storage tanks that will be eventually at higher levels.

109

1. Simulation of the water flow Generation through random points Number of calculation per line per slope: 300 Number of points: 1.800

Number of calculation per line per slope: 600 Number of points: 11.800

2. Simulation of the water flow Generation through an orthongrid grid of points Number of calculation per line per slope: 200 Number of points in the grid: 2000

110

Number of calculation per line per slope: 600 Number of points in the grid: 100 * 100

EXPERIMENT 08 WATER FLOW IN T ROD U C TI O N

CO NC LUS IO N

This test has been made to evaluate the topography of the site in relation to the flowing of the water. The data collected informed us about the presence or not of important areas of convergence. This experiment will be then developed in the step of the generation of the Food Production Towers. The confluence of the streams creates a pattern which is a strongly inspiring us in the design of the settlement.

We realise the possibility to drive the emergence of the city following the development of the topography from the generated pattern. In fact the results we get reveal the formation of spines of water perfectly useful to distribute it between Food Production Centres. This hypothesis has just been abandoned when the logic behind the idea of distributing the water on the surface demonstrates its inefficiency.

1. Arturo TEDESCHI â&#x20AC;&#x2DC;Parametric Architecture, intriduction to Grasshopperâ&#x20AC;&#x2122; Le Penseur

SE T U P The parameters able to set the design of the flow of the water on the surface are the number of calculations per line on slope and the number of points in the grid. The first is able to increase the length of the streams intensifying the density of the emerging pattern. The second is variable not only as a value but even as a configuration. In fact two starting hypothesis are formulated, one consider the water flow generated by an orthogonal grid of points. In the second hypothesis the simulation begin from random points. The tools used to realize the digital experiment is a Grasshopper plug-in, specifically the Calculate Flow Path by Carson. This tool generates from a grid or from a random set of points a same number of vectors which change their direction when they meet the surface. At this point the vectors starts to follow the downwards direction of the topography.

RESU LTS The results are not so different in the two tests. The main collecting water areas remains identically distributed in the topography. The more interesting observations are the ones related to the areas of convergence of the flows which, going via the path of least resistance down the sloped surface, generates spines where the water stalls. This is more evident in the case of random distribution of points. The best results are related with the increasing of the density of the pattern setting the resolution of the curve output. The low the value to more rigid the curve.

111

3% DRINKING

19 % TOILET

39 % 7% OTHER USES

PERSONAL CLEANING

1,0 0,8 0,6 0,4 0,2 0,0

HOUSE CLEANING

COOKING

20 %

PERSONAL CLEANING 0.69 Lt per capita daily 251.12 Lt per capita yearly

CLOTHES CLEANING

GREY WATER

Potentially recyclable water

72 % 1.72 Lt per capita per day 630.72 percapita per year COOKING 0.103 Lt per capita daily 37.67 Lt per capita yearly

HOUSE CLEANING 0.103 Lt per capita daily 37.67 Lt per capita yearly

CLOTHES CLEANING 0.344 Lt per capita daily 125.56 Lt per capita yearly

112

DOMESTIC WATER RECYCLE

D E F INIT IO N

T Y PE O F GR EY WAT E R SYST E M

A high volume of water is taken from the environment for human use. Demand for water is rising because the population is increasing, lifestyles are changing and the impacts of a changing climate are becoming more clear. We need to plan carefully to ensure reliable water supplies are available for everyone whilst protecting the natural environment.

Grey water recycling systems vary in their complexity and size but the most have common features such as:

Exploring ways to reduce demand for mains water is essential to ensure a sustainable future for water resources. One of the options is to install greywater systems to substitute mains water use for purposes where drinking water quality is not required.

• some purifying treatment.

The study of the specifics components of the human domestic water consumption informs us about the data that allow us to understand which volume of water we are be able to recycle in our system. The domestic water is normally characterized by its use inside and outside the home: washing the dishes, cooking a meal, laundry, bathing, watering the lawn, and other household activities. The black and the drinkable waters are by definition excluded from this domain.

RECYCL ING G R E Y WATE R Domestic wastewater may be used in the watering of gardens. This may happen collecting water from the kitchen drain, the washing machine or baths, basins and showers. In case that water contains bleaches, disinfectants, dishwasher salt and stronger cleaning products so it should not be used, as they can harm plants and even damage the soil structure. It is then crucial to avoid using grey water on aliments to be used without cooking. Grey water should be used as it is produced and its storage should be avoided in order not to allow the formation of harmful organisms.

• a tank for the purified water

1. April PHILIPS ‘Designing Urban Agriculture’ John Wiley and Sons publication

• a pump system • a distribution system for transporting the treated water All systems that store grey water have to incorporate some level of treatment, as untreated greywater deteriorates rapidly in storage. This happens because grey water is often rich in organic matter such as skin particles, hair, soap and detergents, this provides ideal conditions for bacteria to multiply, resulting in odour problems and poor water quality. The recycling grey water systems can be grouped according to the type of treatment they use.

1. http://www. planningportal.gov. uk/uploads/code_ for_sustainable_ homes_techguide. pdf

O UR S ET T LE MENT In South America the domestic water consumption is according to The World Bank of 54,02 mt3 per year, which amount is almost the half compared to the usage of USA. Calculating the single uses, the percentage which composed the grey water in the Atacama region is of 72% which means 38,89 mt3 per capita per year. In our settlement the global annual saving will be so of 972.360 mt3 per year. In this specific research is crucial to define exactly the amount of water saved by the residences because every single drop of saved water will significantly help in reducing the fog catcher surface requirements.

1. http://cdn. environmentagency.gov.uk/ geho0511btwc-e-e. pdf

http://data. worldbank.org/ country/chile

113

114

Chapter four

Design Proposal

115

TOWER EVOLUTION

- FCSA / PSA ratio: 0.12 - Prod. for 425 people

- FCSA / PSA ratio: 0.17 - Prod. for 662 people

- FCSA / PSA ratio: 0.44 - Prod. for 1047 people

FCSA: Fog Catching Surface Area PSA: Production Surface Area

116

117

TOWERS OPTIMIZATION

- FCSA / PSA ratio: 0.37

- FCSA / PSA ratio: 0.39

- FCSA / PSA ratio: 0.43

- FCSA / PSA ratio: 0.38

- FCSA / PSA ratio: 0.43

- FCSA / PSA ratio: 0.44

FCSA: Fog Catching Surface Area PSA: Production Surface Area 118

119

FOOD PRODUCTION TOWERS_ SECTION Sun exposure

Sunlight

Housing blocks

Food production tower Production tower

1.1 Conceptual diagram of the cut plan in the tower Housing blocks

Section plane

Fog catching Fog Catching Surface surface

Prevailing wind

Vertical Farm Vertical farming stories

~~~gniK-yrF~~~

Market Market basement

Water from houses

Underground Tank water tank 1.2 Section of the tower with the nets envelop

120

121

FOG CATCHERS ADJUSTMENT

Pipe diametre 100 mm

*Minimising the evaporation process and speeding the water droplets travel to the gutter by using 1 metre Hight of the fog panel units

Pipe diametre 300 mm

1.1 Fog panel unit

FOG PANEL UNIT *Minimising the evaporation process and speeding the water droplets travel to the gutter by using 1 metre Hight of the fog panel units

Nets

Water droplets Water flow/ gravity force

Water ďŹ&#x201A;ow in the fog panels to the Small gutter underground storage

Openings in the main gutter Main pipe

Water ďŹ&#x201A;ow in the fog panels to the underground storage

122

123

FOG PENETRATION IN THE SITE Atacama Desert

Fog Area Arica

Iquique

Deeper fog penetration Tocopilla

FOG Chile

Arica & Tarapaca

Border of the fog penetration area

124

Calama

North of Arica

6 m/s

1 m/s

125

FOOD PRODUCTION TOWERS GENERATION IN THE SITE

ws ws

m Distance 01_Minimum Distance w = 5 * Tower footprint Wind Shadow = 5 * Tower footprint 80 m2 Footprint > 80 m2

m Distance ance = 400 mt

Highest Point in the site

02_Maximum Distance Walking Distance = 400 mt

Lowest Point in the site

03_Lowest Point in the range Y <<

Food Production Towers generation

Point in the range

Food Production Towers generation

126

127

NETWORK ALTERNATIVES

128

129

POPULATING STRATEGY

130

131

HOUSING TYPOLOGIES

132

133

134

Chapter Five

Evaluation &

conclusion

135

136

Critical Essays

137

138

Bibliography

139