Terra Nova Ayiti Landscapes Between Urbanization And Agriculture
Terra Nova Ayiti Landscapes Between Urbanization and Agriculture Master Thesis Florian Strauss, WS 2011|2012 Technical University Munich | Faculty of Architecture Institute of Urban and Landscape Design Chair of Landscape Architecture and Public Space | Prof. R. Keller Supervision through Univ. Prof. Regine Keller Univ. Prof. Christian Werthmann (GSD Harvard) Dipl.-Ing. Thomas Hauck Dipl.-Ing. Juliane Schneegans www.lao.ar.tum.de ©2012. Florian Strauß Chair of Landscape Architecture and Public Space
Content intro
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analysis
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scenario approach
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common problems
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concept
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resilient framework
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masterplan
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landscapes between urbanization and agriculture
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intro
„Piti, piti, wazo fe nich li.“ Little by little the bird builds its nest. Haitian Proverb 5
B
eing one of the poorest coun- of the agriculture in the plain lies fallow. The different Elements like Biodrainage tries in the world, Haiti has to Landslides, earthquakes, liquefying soils Strips and irrigation channels with riparface big challenges over the and devastating flood events struck Port- ian vegetation are simple and proofed next decades. New homes au-Prince since centuries. Especially the agricultural techniques which were not
are needed for the many people who sprawling northern settlements in the only cheap but easy to apply. The interhave lost theirs due to the excruciating Plain are highly exposed to soil liquefac- action of these elements decreases the earthquake in January 2010. But also the tion and flooding.
risk of flooding and soil liquefaction, and
rapid growth of the Haitian Population, As the pressure on the government to increases meanwhile the productivity of mainly concentrated on the metropoli- create new homes is rising, there are first agriculture and biodiversity over the uptan region of Port au Prince, raises the residential and industrial project being de- coming decades. The design of a landneed for further residential development. veloped in and around Zoranjé, a former scape, which can be both urban – with Nearly all Haiti is deforested. The result- social housing project in the north west- an improved resilience - and agricultural ing high risk of landslides concentrates all ern Plain. The current practice, to elevate – with a high productivity – takes into acthoughts on new development on the few the ground level in the plain by one meter count that the future of Haiti, and espeplains of the country. But these plains are through dumping and compacting grav- cially of the Cul-de-Sac plain is still uncerhighly affected by the periodically return- el arises several questions. Is this raise tain. “Terra Nova Ayiti” imagines a resiling hurricanes and flood events. Finally enough to protect the inhabitants from ient framework of Landscape Infrastructhese plains are the most fertile areas of flooding and liquefying? Can there any- tures, buffering extreme rainfall events the mountainous country and therefore thing be grown on the compacted founda- and storm surges, stabilizing the weak the only chance to get emancipated from tion which would give the inhabitants the soil, creating habitats and raising the agrithe food imports.
opportunity for small scale urban agricul- cultural yield. The proposal does not draw
Port-au-Prince, the countries capital is ture?
a picturesque design of one possible fu-
located in the “Cul de Sac Plain”, once From this starting Point, “Terra nova Ayiti” ture situation in the plain, but a system, the most productive agricultural area in proposes several landscape interventions that is flexible enough to absorb all differthe former French colonies. Today most in the vulnerable “Plaine de Cul-de-Sac”. ent thinkable scenarios. 6
access to clean water
less than 50%
1.000.000 frequent
people homeless due to 2010
earthquake
only 1.5% forest cover haiti | domrep 7
housing about
80% informal
hits by hurricanes
waste
collection or disposal system
dysfunctional
ooding affected more than
less than
30% have access to toilets
300.000
highly people died due to 2010 10.000.000 disturbed ecosystems earthquake people in the past 20 years
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analysis
Haiti‘s population is expected to grow up to 16 million inhabitants until 2050. While the rural part of the population will slightly decrease, the urban population is expected to double in the following decades. The main growth is expected to concentrate on the metropolitan region
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of Port-au-Prince. From its today 2.5 Million inhabitants, experts assume, that the population will grow up to 7.5 Million inhabitants during the next 40 years. Haiti is to 75% covered by steep mountains. Haiti is nearly totally deforested. No roots and vegetation is stabilizing the mountain
soil. High risk of earthquake and flood related landslides have always forced the urban development into the countries fertile but highly flood affected plains. Haiti’s urban population will grow rapidly. This arises the question, where all the new inhabitants shall live, in which
direction shall the government guide this upcoming settlements? The deforested mountains are exposed to landslides and the development of new residential projects in the hills is more expensive than in the countries plains. But these plains are flood affected and due to a high aquifer, frequently exposed to soil liquefaction. The coastal regions, former classical residential estates, are expected to suffer most from a projected sea level rise of about 1 Meter in the Caribbean sea. With the growing population, the competition between haiti’s aims for residential, agricultural and natural development will increase significantly.
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Productivity
FERTILE SOILS For agricultural use 13
Flood Risk
FLOOD PRONE AREAS The Haitian Plains 14
P
ort-au-Prince has an average housing density of about 25.000 People per km² in mainly two or three storey buildings. While in Europe, people have in average about 42 m² living space each, a citizen of
Port-au-Prince has only 2 m². Even before the crucial earthquake in January 2010 the provision of basic infrastructures in the city was highly dysfunctional. Only 25 - 50% of the cities population have access to clean water sources. Only 30% have access to sanitation facilities. Although all the NGOs and relief organizations have made huge efforts in rubble clearance and reconstruction since the earthquake, still about 1.000.000 people were living in T-Shelter camp sites scattered through the city. The cities infrastructure is outdated and its development was left behind the rapid population growth during the 20th century.
The cities main roads are frequently congested. Only 25% of the 160 Million tons of garbage produced daily in Port-au-Prince were officially collected and dumped. About the half of the remaining 75% is locally burned. Many garbage remains unprocessed in the streets, ravines and storm water channels. Especially the congestion of important flood protection channels is thought to be responsible for many deaths during flood events. Particularly the informal settlements of Portau-Prince are highly affected by floods through the frequently occurring extreme rainfall events. 16
Port-au-Prince 1967
Port-au-Prince 1994
Port-au-Prince was founded 1749 as a small harbour in the a future city development are restricted by the topography and protected bay of Gonaives. The city, located in the Cul-de-Sac the sea. Only the northern Cul-de-Sac Plain may be suitable Plain between two parallel mountain chains, did grow rapidly for a city extension. Yet today, there is a significant housing from a small fortress to the countries largest city. Today, the pressure on the plain recognizable. Once the most fertile and city‘s extension arrived at the feet of the northern mountains. productive place in the french colonial empire, the plain today The actual and the expected rapid growth of the city‘s popula- lies fallow. Port-au-Prince suburbs are sprawling loosely northtion arises the question, where Port-au-Prince can grow and wards through the plain. Because of the high demand for new develop further on. South- and westwards, the possibilities for residential development, some first projects are being raised in 17
Port-au-Prince 2012
Port-au-Prince 2050?
the vulnerable plain. For example a social housing project in intense agriculture practice in the plain, salt accumulation in the ZoranjĂŠ or an industrial cluster called NABATEC, at the northern upper soil will increase and productivity will further decline. The outskirts of the city. The reality and the population projection agricultural yield will decrease and it will be even more difficult shows, that there is a high probability for a future urbanization for the farmers to compete with prices of the world market. It in the western Cul-de-Sac Plain, the area which is in focus of can be seen in many countries particularly of the thrid world, this Thesis. But an urbanization of the plain is very problematic. that these conditions often lead to informal residential developThe new settlements would be highly flood and soil liquefaction ment, initiated by landlords, unofficially subdividing and selling affected. But with continuation of the current, irrigation based, the unproductive agricultural estates. 18
„Various irrigation systems existed in the Cul-de-Sac from the 1730s [...]. In all, hydraulic systems irrigated fifty-eight plantations, [...] nearly half of the Cul-de-Sac Plain. That flat and well-watered plain, with its lush and regularly laid-out fields and its straight and well maintained roads, must have been a remarkable sight In 1789.“
McClellan III J. (2010): Colonialism & Science – Saint Domingue in the old regime. P.72 19
CUL-DE-SAC PLAIN Was a highly productive agricultural landscape during the 18th and 19th century
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Cul-de-Sac Plain 21
The Plain was once the most productive acreage of the french colonial empire. At its heyday, sugarcane and coffee was produced on over 180 plantations through the whole Cul-de-Sac. Today most parts of the plain lie fallow. The historical traces of the agricultural use were mainly overgrown. Old irrigation channels, which ranged the plain like a fine mesh were still visible in orthophotos. Rectangular roads and waterways do indicate the former network of agricultural supply structures. The image on the left shows the view towards west in direction to the Dominican Republic. From Port-au-Prince a loose sprawl of suburban settlements is growing through the plain, ending in Canaan, a
Project area
young informal settlement. Canaan grew mately 10.000 years ago, was elevated liquefaction. Historical sources confirm, rapidly up to estimated 80.000 inhabitants above the sea by the sedimentation initi- that already past earthquakes, like the so after the devastating earthquake in Janu- ated by the two rivers, Grise and Blanche. called quake of Port-au-Prince in 1770, ary 2010. ZoranjĂŠ, a former social hous- The alluvial deposits of the two rivers are caused extended liquefaction in the plain. ing project right in the center of the plain, about 50 to 100 Meters thick. In a com- Houses, plantations and even small vilis today one of the housing development bination with a high aquifer through the lages sunk into the ground. sites in the northern plain. The plain, lo- plain, in some places only about 2 Meters But also land- and oceanside flooding encated below the sea level until approxi- below ground, there is a high risk for soil dangers a future urbanization in the plain. 22
The Haitian population will grow signifi- de-Sac plain are currently waiting in the cantly over the next 40 years. This growth wings. A major housing project in Zoranjé will mainly be concentrated on the metro- has already been realized. Although inpolitan region of Port-au-Prince.
ternational experts, who were involved
The surrounding steep mountains were in that planning process, have strongly already urbanized to a dangerous degree. advised not to urbanize the western part In the north, a loose, carpet-like suburb is of the Cul-de-Sac plain without approprialready sprawling through the plain until ate planning and risk management, furthe feet of the northern mountain chain, ther projects in the plain are developed. surrounding Port-au-Prince. Central dis- To protect new settlements from floods tricts of the city are populated at a high and soil liquefaction, an approximate 1.5 density. On average, 25,000 residents meter thick gravel foundation is poured, live on a km². Therefore a strong compac- then the homes are built upon that. A simtion of the cities central districts is very ple gravel foundation does not protect unlikely in regard to the following popula- against damage caused by liquefaction. tion growth. There are only a few areas, The groundwater from wet soil layers unin which the city can grow in future. The der the foundation would be still unstable Cul-de-Sac plain, former granary of Haiti in a quake. Significant subsidences of soil and once the most productive agricultural in the event of an earthquake should be area in the French colonial empire seems expected. According to the Department to be the last area in which an expan- of Soil Mechanics at the TU Munich the sion of Port-au-Princes is possible. With only construction feature that would surethe earthquake of 2010 the pressure on ly protect against liquefaction, is a systhe government to initiate housing proj- tem of drilled and drained gravel cores up ects arouse. Several projects in the Cul- to a depth of 10 meters, combined with 23
FLOODRISK Combined ocean- and landsides 24
a deep compaction of the sandy soil in ond World War have shown that successthe vicinity of the hole. The holes should ful revegetation can only be achieved if have a distance of 5 - 10 meters. This the valuable topsoil is removed and empredictive measure would arise the build- bedded besides the gravel foundation, to ing costs of each of the projects in the cover the compacted gravel after with the plain that much, that it would get impos- stored topsoil again. A seamless vegetasible to finance them. In addition, the hy- tion has adapted to the final piles of rubdrology of the plane is strongly disturbed ble only after several years. But the vegthrough the gravel mounds. Watercours- etation cover is of a central importance in es are blocked and stormwater runoff is the new residential areas to regulate the limited through the gravel volumes. It can microclimate, reduce runoff as well as wabe assumed that the gravel landfills are ter and wind erosion. not planned in regard of hydrological con- Through the coverage by gravel, many nections and the overall flood risk in oth- valuable farmland gets lost. A productive er parts of the Cul-de-Sac plain. Informal urban agriculture, as it is vital for many settlements that will in all probability be Haitians, is not possible on these heaped established beneath the formal, elevat- „gravel deserts“. Due to the geographied ones, are thus exposed to increased cal location of Port-au-Prince, the cul-deflood risk. Can these compacted gravel Sac plain is the last potential settlement surfaces can be planted again? Where area that can accommodate the expected will the gravel, necessary for the founda- strong growth of the city. At the same cultion to be mined? It is obvious that fertile de-Sac plain is particularly strong affecttopsoil gets lost through the heaping of ed by flood events and earthquakes. The gravel. Findings from the greening of rub- current practice of building will not meet ble mountains in Germany after the Sec- these threats. 25
LIQUEFACTION RISK Areas affected by soil liquefying 26
The Cul-de-Sac Plain was dedicated to is influenced by the sea. Due to the closeirrigated agriculture since more than 150 ness to the coastline, the salt concentrayears. There was neither a system for tion in the aquifer of the Cul-de-Sac plain crop rotation nor drainage implemented. is particularly high. On many of the plain’s acres, sugarcane, By irrigating a field, the irrigation water ina plant with a particular high need for irri- filtrates the soil and usually starts to seep gation water, was cultivated for centuries. away. The high evapotranspiration rates The climate of the Plain is arid - evapo- and aquifer levels in the plain cause the transpiration is higher than precipitation. vaporization of the irrigated water and the But nevertheless, the average aquifer in leeching of groundwater towards the surthe plain is high. According to a report on face. Therefore, the dissolved salt accuthe geology of the plain the ground wa- mulates in the topsoil. ter table is in some parts of the plain only The Rivers Grise and Blache do carry about two meters below ground. Irriga- and enter approximately 2.8 tons of salt tion based agriculture with a high aquifer per irrigated hectare. Without drainage are conditions that foster soil salinization. system, the irrigated soils accumulate so Many parts of the plain are in the mean- much salt in only 30 years, that the growth time that affected by salinization, that a of plants would be significantly restricted. agricultural production is nearly impossi- Salts which are leeched out of the aquifer ble. These areas are hatched in the map and accumulated in the top soil are in this on the right. Irrigation water contains dis- calculation not included. With a well worksolved salts - regularly they are in a low ing deep drainage system, the salt conconcentration. Groundwater too con- centration in the irrigation water could be tains a specific concentration of dissolved negligible. salts. The Aquifer in the Cul-de-Sac Plain 27
SOIL POTENTIAL For Agriculture 28
scenario approach
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STAKEHOLDER In the future development process of the north western Cul-de-Sac Plain
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T
he future of the Cul-de-Sac The presented scenarios are developed The many Haitians who have lost their plain is not easy to predict. around the influence of different stake- homes during the earthquake are sufferWether the plain will be fur- holders. Depending on their will, strength ing under the deficient conditions in the ther used in agriculture or will and power, the plain will further be urban- tent camps. The people want houses as
be developed to a new residential or even ized or used for agriculture. Together with quickly as possible. Parts of the Plain are industrial district in the north of Port-au- an experienced local and according to a already loosely urbanized. The Residents Prince depends on the actions of many recent Situation Report of Port-au-Prince face the same problems as the most Haistakeholders. The way for Haiti to a whol- from the UNDP, the different stakeholder tians. The basic infrastructures, like water ly democratic and transparent country, and their main aims were identified. In or- supply are often not granted. In addition with less corruption and a fully function- der to simplify, the different stakeholders to that, the residents are exposed to freing legal system may still be long. In the were pooled to coreunits.
quent flooding and soil liquefaction during
focus of this design approach are three The Government is actually seeking quick earthquakes. Their main objective is an possible different scenarios for the Cul- solutions for the problems related to the improvement of their current conditions. de-Sac plain. The scenario method has earthquake of January 2010. Thereby is The few big landowner of the plain are acthe advantage, that you do not have to the main objective to preserve political tually waiting for the confirmation of ownconcentrate on only one possible future stability through the provision of housing ership rights by the haitian government. but can compare different possible situa- and basic infrastructure. Short term solu- Their interest is making a possibly high tions - especially when it is that difficult to tions were dominating. Although the main profit out of their land. Whether this would say, which of the scenarios would be the objectives of the aid agencies are to spe- be achieved by agricultural use or by urbest to happen. Design approaches fol- cialize in humanitarian assistance and to banization is not that relevant. The haitian lowing a classical method, proposing the assist economic recovery, most of them and the foreign private sector is looking one and only sublime solution do often are actually shifting from humanitarian re- for secure possibilities with high rentabilnot meet the requirements of such com- covery to urban reconstruction. Lacking ity to invest in. A sustainable developplicated context like Haiti’s political, eco- experience in this field, many projects are ment, which has probably a lower interest nomical and institutional situation.
missing a sustainable long term vision. is considered only by a few of them. 34
The first scenario assumes that in future, a strong government would implement a masterplan, following the recommendations of the regional planning department. Housing in the plain would be restricted. The Plain would be devoted to agricultural uses. The growth of Port-au-Prince would be directed to secure areas or would be bufferd by the promotion of other metropolitan regions. 35
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This scenario anticipates the development of the plain under current conditions. The shared influence of NGOs and government with abscene of an incepted masterplan would lead to a patchwork of housing, industrial, agricultural and commercial uses. 37
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The development of the Cul de Sac Plain in the third scenario is mainly dominated by landowners and investment from the private sector, while the government and the NGOs have only little influence. This constellation could lead to a high urbanisation. 39
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common problems
The three different scenarios would have soil salinization will further increase. This different results. In the first scenario, would consequently lead to a reduced many people would find work in the agri- yield, less productivity on agricultural arcultural sector. About 5000 Haitians could eas and a increased risk of informal debe fed with the yield of the north western velopment on these, then unproductive Cul-de-Sac Plain. In the third scenario, fields. much more People would mainly work in Another common problem through all industrial and commercial sector. Large the scenarios is a loss of biodiversity parts of the Plain could be used for res- by maintaining the common agricultural idential development. Informal develop- techniques, through deforestation and ment would be very distinc and on very through a intense urbanization without dangerous sites in the third scenario. But consideration of ecological issues. The it is expected to be present in the other constant loss of habitat and the disturtwo scenarios as well. With the scenario bance of ecosystems would further rebased approach, the benefits of all sce- duce the plains resilience against natural narios could be described. While compar- hazards, the attractivity of the country for ing these three different future situations, tourists and also the variety of animal and it was obvious, that all scenarios share plant species. same problems - of course in a different The identification of these common probintensity but always present.
lems, which were present in all three sce-
In all scenarios people would settle in narios, was the starting point for the dehighly flood affected areas. The risk of soil velopment of a system of strategic reacliquefaction is present through all scenar- tions, interacting to reduce flood risk, soil ios. Due to the ongoing agricultural prac- liquefaction, productivity and biodiversity tice in the plain, it is very likely, that the loss. 43
FLOODRISK Most parts of the western Cul-de-Sac Plain are exposed to frequent flooding
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LIQUEFACTIONRISK Most Parts of the Cul-de-Sac Plain are highly affected by soil liquefaction
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DECREASING PRODUCTIVITY Salt accumulation increases due to irrigationbased agriculture
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BIODIVERSITY LOSS Deforestation, monoculture, and pollution will further decrease diversity
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concept
The western Cul-de-Sac plain has both, the potential to sustainably accommodate the future urban growth of Port-au-Prince as well as being restored again as the fertile granary of the city. The previously identified problems which are common to all scenarios are faced by four landscape infrastructure elements. The reforestation of the coastal and riparian forests, the vegetated irrigation and drainage channels, the fishponds and the biodrainage strips will interact in a robust framework in which the plain can be flexibly developed into the described scenarios. The proposed elements are tried and tested techniques of agriculture especially in poorer countries. They may improve the productivity of the landscape and can make the landscape more resilient and secure for a possible future settlement. The aim of the draft is not, to completely avoid the negative impact of floods and earthquakes in the Cul-de-Sac plain, but to allow a future urbanization or agriculture, in which the consequences of flooding and soil liquefaction are reduced to a 53
manageable level. To realize that, construction methods are chosen that are inexpensive, simple and solid. „Terra Nova Haiti,“ is not understood as a landscape which is a victim of natural hazards. It is rather that resilient due to the proposed landscape infrastructure elements that a life in the Cul-de-Sac plain is possible, which is consistent with the potentials and the hazards of Haiti. The money which is used today to establish new settlements with an alleged flood protection could better be used to install a network of irrigation and drainage channels, retention volumes and surface drainage based on alleys of leeching trees. This would allow a much more productive and sustainable agriculture and would guarantee a necessary minimum of space for future urban infrastructures in upcoming settlements and ensure flood protection and provide stability to the liquefaction prone soil. The work proposes an efficient, resilient network of these landscape infrastructure elements and shows meanwhile, which
positive correlations between the respective elements can result in an agricultural or in an urban scenario. A landscape is being proposed that can be simply transformed from an agricultural use into a future city. A grid, in which those elements can interact effectively, is developed by regarding the existing and the historical morphological landscape structures of the Culde-Sac Plain. Core unit of this grid is the Carreau, an agricultural square measure, which later will be the basic building block - the block in the new city. Beneath the installation of a solid landscape framework until 2050, the work thus proposes a land consolidation and an adjustment of the ownership structure towards a more flexible and productive landscape. Through the scenario-based, processoriented approach it is possible to identify the measures that are necessary for a sustainable development to a robust and productive landscape, with or without the city.
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The first element, a protective forest on function as filter- and flood protection the coastline and the banks of the plain’s planting and would increase the recrerivers would counteract primarily the risk ational value of the plain significantly and of flooding, soil liquefaction and loss of thus increase the tourist attractiveness of biodiversity. The central importance of the landscape. Within a development cythis element is the reforestation of the cle until 2050 the shoreline would be conmangroves that once covered the coast- solidated and protected of erosion. Manal belt of Hispaniola and protected from groves and riverine forests are particularstorm surge and tsunami waves. From ly rich ecosystems and reforestation conthe buffer forests both, the urban and the tributes most to the increase of biodiveragricultural scenario would benefit. Agri- sity. The plain has a high wind potential cultural yields would increase, for exam- because of the chimney effect caused by ple through additional income of forestry, the two mountain chains. After an initial fishing and hunting in this element. Riv- phase, until the soil is stabilized by vegeerside forests protect against tidal waves tation through root penetration and water and buffer flood water like a sponge. In extraction, it could be possible to generthe urban scenario, the forests could ate wind energy in the coastal forests. 55
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A further element are the riparian vegetat- ter and clarify or carry it out to any further ed irrigation strips. The strips provide the treatment. In the dry season the fields farmland with irrigation water, the riparian could be supplied with water, and drained vegetation protects against erosion and during the rainy season. In the case of can also be cultivated. Besides firewood flooding, the irrigation strips could distribthe riparian vegetation provides berries, ute the floodwater and buffer. While this nuts, oils and fruits. Within an urban de- element is developed into a vegetated velopment, the former irrigation channels, flood protection and irrigation channel the would follow new tasks. The recessed productivity and biodiversity of the landchannels could be used by residents for scape increases. By the drainage effect recreation and would be also retention in rainy seasons, the water content of the volume to mitigate the impact caused by soil is constantly reduced, which would flooding. It would also be conceivable that prevent from both the salinization as well the channels take up the urban gray wa- as the risk of liquefaction. 59
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The proposed aquaculture do support the increasing urbanization fish ponds could agricultural production especially on very absorb and clarify municipal wastewater. wet or salinized farmland. Freshwater fish The supply of nutrient-rich black water inponds are a habitat for various birds and creases the productivity of fish ponds cona proposed freeboard of about one me- siderably. Over the years, with increasing ter would also provide retention volume wastewater supply the productivity of the to relieve in the case of flooding. With ponds would grow permanently. 65
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Last important element are the Biodrain- risk of soil liquefaction. But there are furage alleys which increase productivity ther synergy effects between this element and do counteract in particular soil liq- and an urban or agricultural development. uefaction. In the arid climate of the plain, The alleys can be used for forestry, will due to the high ground water level, most break ground winds, and protect, just like irrigation water does not seep away and field hedges from erosion. runoff. The high evaporation rates even In the urban scenario, the rows of trees pulling groundwater to the surface, result- could be thinned out to an urban bouing in a high salt concentration in the top levard. The trees provide shade and layers of the soil. Biodrainage alleys - the strengthen the surrounding soil. plantation of water pumping trees, like A historian wrote about the great earthEucalyptus - notably lower the groundwa- quake of 1770 in which no building in ter table and do break through this cycle. Port-au-Prince remained intact: In irrigation-based agriculture, this is an „[…] The public edifices, such as the Goeasy and cheap approach to reduce soil vernment building, […], the Counsel builsalinity. Due to the water extraction and ding, and the most solid structures, like the increased root penetration the topsoil the New
church, and private houses,
consolidates. The chair of soil mechan- were no more than heaps. Only the rows ics of the TU Munich had confirmed that of trees made the streets recognizable the reduction of the water content in the still.” The proposed Biodrainage alleys soil and the intense penetration by roots can thus protect certain city structures reduces physically and mechanically the against earthquake damage. 69
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resilient framework
1 European Pace = 3 Feet
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1 Haitian Pace = 3,5 Feet
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The individual elements interact in a raster-based framework. The coastal forests do buffer storm surges and tsunamis, Biodrainage alleys consolidate the soil and reduce the salinity, the irrigation channels increase productivity and protect against flooding and the fish ponds are another possibility to generate income on unproductive areas of the plain and will later take over the important municipal function of waste water treatment in combina-
Port-au-Prince
tion with a higher yield in fish farming. To translate this model-like approach into a masterplan, a grid was developed. The remaining historic channels and access roads draw a distinguished, dense grid in the plain. This grid is based on historical methods to subsidize the farmland.The plantations in the Cul-de-Sac plain were all built relatively similar. According to historical sources, a typical plantation in the plain was about 1000 paces wide and at least 4,000 paces long. This allowed to
Gonaives 79
reconstruct the old structures. While an European pace is 3 feet, the Haitian pace
why ever - is larger. This was the key to length of 113 meters and an area of 1.29 a measure to lay out the urban fabric of finally understand the significant mesh European Hectare. This acreage corre- the historical cities. But it can be seen as of existing and overgrown channels and sponds with the average field size, a hai- granted that the dimension of the carreau access roads that formerly structured the tian peasant owns. A study of the historic is quite in scale with Haitian city blocks. whole plain. Basic agricultural unit in Haiti city center of Port-au-Prince also showed Based on a morphological study a grid is the Carreau, a Haitian hectare, 100 that this measure can be found in some was developed that complements the to 100 Haitian Paces. Because of this places as a side length of city blocks. It is existing structures relying on a historical deviation, a Carreau in Haiti has a side not confirmed that the Carreau was also standard size, the Carreau.
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masterplan
Current Practice
Landscape Infrastructures U.S.AID has recently restored parts of advantages of the gravel fillings are the old irrigation system in the plain. obvious. The flood risk is only partialWith less than 100$ costs per hect- ly reduced and the landfills are major are, the organization describes on disturbances in the hydrological structheir website, it was one of the most tures of the plane. Many fertile soil reasonable investment that they have will get lost, salinization and liquefacmade in ​​ Haiti. The current practice, tion will remain high. The costs of the to fill the area with about 1.5m gravel proposed landscape infrastructures costs rough and very cheaply estimat- would be less than a development of ed about $ 30,000 per hectare. Dis- the plain under current conditions.
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Scenario O
channels
ďŹ shponds
Biodrainage
Landscape Infrastructures in the Cul de Sac Plain
M 1:5.000
Scenario Tw Windturbines
Biodrainage
Fishponds
Pla
no
fZ
ora
nje
in
all
Sc
en
ari
os
1:5
.00
0
Irrigation Channels
M 1:5.000
Scenario Th Mangrove
Riparian Reforestation
Windturbines
84 M 1:12.500
M 1:5.000
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Landscapes
Between Urbanization And
Agriculture
CARREAU LAKOU Agricultural
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CARREAU LAKOU Initial
CARREAU LAKOU Development
CARREAU LAKOU Final
90
CARREAU CREOLE Agricultural
91
CARREAU CREOLE Initial
CARREAU CREOLE Development
CARREAU CREOLE Final
92
Scenario One + 93
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Scenario Two + 95
96
Scenario Three + 97
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Landscape Infrastructures A placeholder for future urban development The proposed irrigation channels, the biodrainage alleys, the forestal buffer and the fishponds do structure and frame the future Cul-de-Sac plain. No matter what scenario will happen in the upcoming decades, these elements will guarantee a maximum flood protection, soil consolidation which leads to less liquefaction, higher yield through less salinization in agriculture, and a constantly increasing biodiversity. The Thesis so suggests a change in the current strategy for dealing with natural hazards in the plain. Instead of investing much more money, than the proposed landscape infrastructures would cost, to create assumed 100% security and protection of possible flood events, this proposal aims to intervene for a sustainable and manifold beneficial live in the plain. A new landscape in which the threat of natural hazards is to a minimum reduced while the productivity and the biodiversity of the landscape is ensured. 101
The proposed elements address all the identified problems and do act as a placeholder, guaranteeing a minimum of public space and corridors for a infrastructural supplement of the future urban development. Irrigation strips may transform to inner city supply and disposal corridors, may carry freshwater and energy supply lines or may give space for urban agriculture as well as inner city wind energy usage - Or they will just be public spaces in the center of a new and very dense urban pattern, where residents will find room for recreation and play. Biodrainage Boulevards which formerly organized a rural landscape may transform to inner urban boulevards, still draining the adjacent soil and preventing from liquefaction. They might also transform to boulevards in which shade people trade their goods on street markets, or priority lanes might arrange a high speed network of public transport.
Irrigation Channels - Transforming to innerurban agriculture and supplement spots 102
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Irrigation Channels - Transforming to lifelines of innerurban recreation 104
Piti, piti, wazo fe nich li. Little by Little the Bird builds its nest. Haitian Proverb
With this Thesis, methods were identi- ments in the global markets beyond Hai- urban agriculture, they were free public fied that allow a process-oriented design ti’s influence. Nevertheless, the proposed spaces for sports and recreation. They and implementation of the Landscape strategies show a way, how the Cul-de- even could serve as black- and grey wainfrastructures in the Cul-de-Sac plain. Sac plain can be transformed into a safe ter treatment channels. Also the BiodrainWhether the proposed strategies are suc- and highly productive landscape, with or age boulevards protect either adjacent cessful or fail, however, depends in parts without city. In this new landscape the irri- buildings from the earthquake impact and on factors beyond the influence of a plan- gation strips are either lifelines of a highly improve the cities micro climate or they ner. Crucial to the success of the refor- productive rural landscape or urban junc- organize a rural Cul-de-Sac Plain, which estation of the coastal and river banks tion and meeting point close to the water. again will evolve to the highly productive is that alternative fuels for cooking were The urban edge, where haitians can do granary of Port-au-Prince. A Plain with found in Haiti. Only when the charcoal their laundry, where kids can play and exotic riparian and coastal habitats, an which is used as fuel slowly will be re- people can relax in the shadow of the active bird life due to the extended fishplaced by other resources, afforestation riparian vegetation. The channels will ponds - a plain which is of high attractiveprograms will have a future. The success never look same but will always perform ness for tourists and locals. Terra Nova of agricultural development programs de- equally. They guarantee security during Ayiti is a landscape between urbanization pends on political decisions and develop- flood events, they provide fertile soil for and agriculture 105
Biodrainage Strips - Future Boulevards 106
Urban Cul-de-Sac Plain | Irrigation Channels 107
Rural Cul-de-Sac Plain | Biodrainage and Fishponds 108