FUTURE URBAN TISSUES OF CA MAU
CA MAU ARCHIPELAGO
Clusterizing Ca Mau in respond to flooding, saline intrusion and dense centric urbanization Thesis presented to obtain the degree of Bachelor in Architecture and Urban Design
Spring Urban Studio 2016, Ca Mau, Vietnam Hai Tu, TRAN | Hoang Thanh, TRAN | Thi Thuy Tien, PHAM
LOCATION MAP
UNDERSTANDING THE GROWTH OF CA MAU city scale analysis Ca Mau peninsula is situated in the southern most part of Vietnam, between the East Sea and the Gulf of Thailand and the lowest part of the country. Ca Mau city is located in the heart of the peninsula. The topography of the site is quite flat with the highest part of the city being the current city center, whereas the rest of the city are quite low and currently used for productive landscape (Shrimp farms, Paddy field‌) which are facing with the serious problems of flooding. Flooding is one of the most important issues in Ca Mau City. The reason of the flooding is the impact of Sea Level Rise from the seas that affects strongly to the living quality as well as development of the city. Damage up to 10 billion VND each year for water management and development. Moreover, the ecology of the city is now at risk due to the loss of the territory. Besides that, with the low amount of rainfall in dry season which allows saline intrusion to Ca Mau city also causes many serious problem for the economy and the living of the residents in Ca Mau city. Because the land is covered 2 sides by the East and West Seas with different tidal effects to the rivers and canals leading to the water having become more salty and the serious lack of fresh water demands for human habitation in Ca Mau City.
1939 1951 2016 Lowland City Planning
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CITY STRUCTURE ANALYSIS
Even though the city is now at risk of being under the water by the year 2050, the urbanization is growing rapidly, especially in the last 20 years. The logic of the urbanization development is mostly based on the main infrastructure and main canals, rivers and expanding as an octopus’ tentacles and then followed by the grid structure of the French colonial period. With the aim to become a second class city of Vietnam, the masterplan of Ca Mau in 2025 is developed with a concentric model and expansions of hierarchy of old roads. However, the new developments made by Ca Mau government are on the lowlands where the soils are very weak and flooding risk is really high. Although, there are some new ponds made to meet the needs of fresh water demand in the design, however, they lack the logics behind these ponds.
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ia Ra ch G to ing ad He 1
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CITY MOBILITY ANALYSIS
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From the French Colonial period, Ca Mau was planned with a very clear hierarchy of road which connects to other cities by five main highways. The inner city roads was planted with beautiful green lines and currently are activated as commercial services. However, going out of the city center, all these boulevard seem to loss the identities and turn back to the highways with very big road and less green. With the rapid urbanization, the main highways will be consolidated by new habitants. Therefore, infrastructure can be a potential landscape and framework to develop new urban quarters in the future.
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Inter-City Road Primary Road Secondary Road Tertiary Road Agricultural Road
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Source: [1],[2],[3] AHO Student, Ca Mau Hyber (Landscape) Urbanism
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Petro Vietnam
Khi Diem Dam New Urban Quarter [1]
Ward 1 New Urban Quarter [2]
Existing City Center
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URBAN FABRIC ANALYSIS
TV-Radio Station Urban Quarter [3]
Ward 9 New Urban Quarter [4]
Ca Mau Hospotal Urban Quarter [6]
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New Administration Urban Quarter [5] [1]
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From the city scale, there are several new neighborhoods that has been constructing on the periphery of the city which are based on the new developments of main amenities of the city such as airport, hospital, Petro neighborhood,... The new developments has developed with different tissues based on the location and purposes of the private developers for example: Petro Vietnam neighborhood and Ward 9 new urban quarter which contain big blocks, slabs and clear design of public facilities and greeneries, while the others follow the traditional way with townhouses and green streets. Although these new neighborhood are working independently and lack of the connection as clusters around the periphery, they also bring potentials to Ca Mau City as an archipelago concept.
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port Urban Quarter [7] [7]
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HELSINKY PRO 2.0
reference Project
With the same urbanization issue as Ca Mau City that in 2050 the population of Helsinki could grow by 250.000 inhabitants. The new masterplan of Helsinki City redirects the city as the archipelago concept that preserving the northern forests and develop the green structure as separating element to divide into smaller pieces and guide the development of the city as clusters as the southern islands in the sea. Besides that, the making use of the old highways and turn them into the boulevards system by develop new neighborhoods along them.
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HUANGPU RIVERFRONT
reference project
Ca Mau and Shanghai Cities are now facing with a big challenge of polluted water. The riverfronts of Huangpu and Ca Mau Rivers are now ignored by residents and used as waste-water transfer, they are totally dead. From this big problem together with the rapid urbanization of Shanghai, the project tries to bring back the life to the Huangpu riverfront by providing big green open spaces with different activities connecting to landscape as well as cleaning the polluted water via wetlands and landscape condition. From the framework that the system of open spaces and landscape along the riverfront, the new neighborhoods are rose to meet the need of urbanization issue and create a new living standard for Shanghai residents.
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14 CITY SCALE STRATEGY CONCEPT DIAGRAM
CLUSTERIZING CA MAU
city scale strategy
From the city scale context, there are two question raised: How can the city be developed adapting with the Flooding and Saline Intrusion issues in the future? How to meet the need of houses in rapid growth of urbanization in sustainable way?In order to answer these questions, based on the investigation stage that we pointed out the problems as well as the potentials of the site. The concept of developing the city as archipelago city is very suitable and sustainable.First of all, all the highways which are safe roads will be selected as backbones of the new developments and keep all the lowlands for landscape. The new islands will be created along the roads and the main Ca Mau rivers in order to revitalize the river. After that, a new ecological corridor which are canals and constructed wetland will be
“ISLAND� MAKING CONCEPT DIAGRAM
established to interconnect and deal with water treatment for new islands. Then all the highways will be merged with green system and turned into boulevards which are downgraded to have more spaces for pedestrian. Moreover, developing a new mobility strategy to connect these islands by public transports and bike/pedestrian system to make Ca Mau city become a sustainable city. In order to make the concept clear, the islands will be formed with three principles: firstly, topography that the lowlands will be dig to create the ecological corridor mentioned above and make use of these lands to create dike to protect the islands from the flooding; secondly, the scale of the ecological corridor will be not bigger the rivers, finally, trying to keep the existing houses.
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16 CITY STRUCTURE STRATEGY
With the concept of Ca Mau Archipelago City, the city now has a chance to reconnect with the river and adapt with the flooding and saline intrusion issues. New islands are created along the old highways that now are the green boulevards connecting the whole city by public transport and commercial corridor. Besides that, the new canal and constructed wetland system improve and clean the polluted water as well as making use of storm-water in the wet season in order to meet demand of fresh water in the dry season. Moreover, an afforestation strategy is developed following the main canal and rivers which can improve the saline intrusion to the city.
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18 POPULATION DIVISION STRATEGY
With a very fast growth of population, in order to meet the demand of houses for 250 000 inhabitants in 2050 of Ca Mau, the new urbanization will be developed as island floating among the landscapes that the project bring to Ca Mau mentioned above. Each island will be accommodated with different morphologies and programs based on the location of the islands in order to create a diversity in identity of Ca Mau City. The population for each island is calculated based on the requirement of 2 ha per person, it means for each person will have 2ha landscape. With that new standard, Ca Mau resident will have a chance to live and interact more with open space and landscape.
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20 CITY MOBILITY STRATEGY
In order to revitalize the waterfront and sustain Ca Mau City, the mobility strategy aims to shift from the private vehicle of Ca Mau residents to public transport which also connect with the water system. Besides the boulevard systems based on existing highways now are merged with landscape, there will three main spines which has different landscapes and functions are established including Economic Spine connects the whole city with commercial purposes with Petro Vietnam; Cultural Spine along the Ca Mau riverfront which is developed with cultural public facilities; Park Spine links the city center to the new neighborhood of Petro that give people a view to the finger forest and productive landscape from the northern of Ca Mau. Moreover, new public transport system consists street-bus and water-bus from the city center to the Petro Vietnam.
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22 CITY LANDSCAPE STRATEGY
Landscape Strategy of Ca Mau Archipelago is the priority strategy that the project will be developed in order to create a framework for the new developments coming later. The aims of the strategy is to improve the quality of water that will be the key element as identity to reconnect Ca Mau people with water and adapt to the climate changes which create flooding and saline intrusion issues.
Firstly, the ecological corridor will be developed based on the lowland. The new canal will be established by cut and fill process that make use of the digging land to fill the dykes of the islands and make them become safe land. The canal will be merged with the constructed wetland system which is able to clean the polluted water by ecological way. From the strategy, the new neighborhoods will be reconnected with the water and take advantages of the recycle water. Secondly, there will be a new forest system developed following the main canals and rivers from the north and the south of the city which can help the city dealing with saline intrusion and improve the quality of living of the new city. From the north of the city, the main rivers and canals which connect with the Mekong Delta will be forested in order to put the pressure of the fresh water from the delta and bring them to the Ca Mau city and pull the salt water to the sea. In addition, linear mangrove forest will be followed the water ways from the south which take the salt water from the East and West Sea. The mangrove forest has a power to prevent the salt water and protect the land from soil erosion by the characteristics of the roots. Besides that, the afforestation strategy can bring down the temperature and improve the air quality of Ca Mau City.
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WATER UTILISATION CYCLE
24 DRY SEASON PERSPECTIVE
CUT AND FILL PROCESS
WET SEASON PERSPECTIVE
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EXISTING CONDITION AERIAL MAP
UNDERSTANDING THE URBAN DEVELOPMENT site scale analysis Situated on the perimeter of the city’s current form, the site sits in between the city’s center and Petro Vietnam Industrial Zone. In this part, we will be researching as well as providing a perspective on how our site has developed as itself and a part of the city of Ca Mau. We will focus mostly on the development of current existing settlement; the variety of typologies and their pros and cons; as well as the urban forms it is taking. Through that, we would like to express our impression on the site, reflect that on the strategies we proposed for the city in order to achieve coherence and best solutions for the site’s issues.
CLUSTERED URBAN DEVELOPMENT
RIVERBANK AND FLOODING ISSUES
28 EXISTING TYPOLOGIES
DISCONNECTED, OVERSIZED AND DISREGARDED LANDSCAPE
Through our series of mapping, we have come to realization that the site is developed in a clustered strucure with ,apparently, no relation to one another. The clusters are developed individually with a very infrastructure-heavy base. Rectangular blocks are used throughout the newer investment to utilize the most amount of surface available. This has lead to a very disconnected development that is generic in Vietnam - applied to most of the bigger cities of the nation -, disregarding the identity and surrouding conditions. Along with the settlement, a major amount of green spaces are disregarded and acting as backyards for the houses crowding along the roads and streets. These green spaces consist of natural landscape along with productive ones that not only can be used as urban parks but also space for water during the flooding season. Moreover, the riverfront, the core of Ca Mau identity is being left asides as the backyards of informal houses, shipping docks and empty lands. Along the river is a very busy street with life filled in it but acts as an individual entity and the river plays no part of enriching the urban experience, hence not bringing it values to the more inner land.
MORPHOLOGY PATTERN
To further evaluate the urban fabric, we noticed that since the site is within the perimeter of new urban development, the urban fabric forms grids that counteract with the older developement, which is more spontaneous and follow the pattern of the productive landscape lots. Each of the development has it perks, but with no correlation, the whole area is lack of consistency in its appearance. On a smaller scale, we have looked into the currently used typologies. They range from low appartment buildings to typical rowhouses and informal poor-quality waterfront houses. These typologies, no matter how new, has not solved the problem of flooding and saline intrusion of Ca Mau. The houses along the water are too low for the water level of the flooding season, so people end up living in the flood every year. The newer houses, even though not suffering much from the flooding, add to the problem by putting more asphalt on the surface, thus preventing the water to get absorbed into the ground. Rainwater cannot get into the lower levels of soil and freshwater is not enough to outbalance the salt level in the earth, flooding and saline intrusion will get worse as consequences.
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Living with Flood
30 Connecting people with Water
Interacting with Landscape
Changing Water Cycle
Bring the Temperature Do
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RESPONDING TO FLOODING AND SALINE INTRUSION
vision for site
Cleaning Polluted Water
Enhance Open Space
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URBAN FABRIC STRATEGY
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INTEGRATION OF CLUSTERED DEVELOPMENT
site scale strategy
As discussed in the analysis for the site, and the proposed structure of the city of Ca Mau, it is best suited for the stie to develop in a clusters-based structure. The first step is to define the island. By integrating the landscape within the site with the river, the canals and the surrounding productive landscapes, a thorough natural landscape will divide the area into different islands, selected by their functions as well as urban forms, with different identities. The “islands” are defined by the densification of housings within the “sea” of natural and productive landscapes. The edges of these clusters are also determined by the elements present at the specific locations, ranging from key urban spaces at the cross of
SITE STRATEGY CONCEPT DIAGRAM
infrastructures and landscape; to waterfront that connects directly to the main road of the city; to the opening of inner landscape to the outer ones. We also structure these spaces accordingly to the urban experience we would like the users to have. Lastly, the urban fabric of each island are defined based on the existing structures. They vary from rowhouses with setbacks for collective spaces; to community spaces connecting longitudinally and thorough to complement the bond within the neighborhood. We would like to emphasize the use of collective urban spaces to provide intimate and on-the-spot urban activities.
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Each of the “islands� has its own identity in urban development. On the one where there are Khi- Dien-Dam residential area, administration facilities, it is classified as one of the most important node within the whole area with large building blocks for offices, social infrastructures as well as being the intersection of the two largest roads, leading the inside of the site to the riverfront. The closer the buildings are to the main roads, the bigger they are to adapt with the scale of mobility. Along with that, a series of linear collective spaces are provided to balance those of infrastructure. The island on the riverfront is structured with smaller houses that are elevated from the ground to best cope with the flooding seasons as well as providing public spaces underneath the dwellings leading to the river. Another one of the main islands are pre-structured with grid and generic rowhouses, we chose to rethink this and put the use of setbacks into the blocks. This will create a variety of facades as well as adding more intimate collective spaces for all of the residences.
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Park Mangrove Wetland Water Productive Landscape
36 LANDSCAPE STRATEGY
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An important point of the design is to define what separate these islands. We have decided that it is best suited with the context of Ca Mau to have a small canal with wetland along it. Canal because there will be more space for water and moving water will solve the problem of mosquitoes. During the dry season, this canal will be kept at a low level of water to prevent drowning and still maintain freshwater to respond to saline intrusion. When flooding season comes, this canal will help relieve the pressure received by the other older canals that have not been able to fulfill their purposes. The placement of wetland along the canal is to provide a natural cleaning mechanism for the water. Stormwater as well as other kinds of water put on the ground will be purified before they come into the canals and will keep on being cleaned after coming out into the rivers. Throughout the canal, the spaces shift and vary with a rhythm of open and close spaces. At places, it will be faced with building blocks to provide waterview for the balconies. At others, it will be a core for urban activities, a place where people can interact with the water, where they can hold events. And at some places, the space with be a combination of both open and close. The sequences are created to provide users with the most various urban experience.
[1] CANAL SPACE SEQUENCE
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[6] 38 CANAL SPACE SEQUENCE
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Another important element within the site is the riverfront. As explained in previous parts of the thesis, the aim of the strategy is also to revitalize the riverfront that was once overlooked. The methods that we came up with are all based on the same principle, to allow people to come and open up the riverbank to everyone. Houses along the riverfront are elevated with the first floor dedicated to open spaces. Urban spaces are organized where relevant to act as triggers for the rest of the space along the river as it is also closed sometimes through the use of some other kinds of building blocks. Another aspect of the revitalization is the use of water buses. Docks are placed along the river to attract people to use this soft mobility. This brings either another kind of sightseeing or simply offering the people coming to work at PetroVietnam an easier and nicer way of going to work. Details like the use of windmills and solar panels are also put along these spaces by the water. Shading devices would be equipped with solar panel and windmills to provide energy for community lighting at night, being sustainable and an adaptation to the flooding issues.
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RIVERFRONT SPACE SEQUENCE
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Main Road Neighborhood Street Pedestrian Path
40 MOBILITY STRATEGY
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The roads and streets hierarchy is also a focus of the strategy. The three main roads of the site are divided into 3 profiles: 1. The commercial spine with 6 lanes of cars and motorcycles. The sidewalk will be wide to best cope with the largeness of the road. The first floor of every building will have a setback of at least 5 meters to provide shaded public space for people to walk. 2. The riverfront road with 4 lanes of cars and motorbikes. The sidewalk on the river side will be enlarged together with the open space underneath each of the housing units. The other side will be the basic sidewalk with trees for shading. 3. The woodland road with also 4 lanes of cars and motorbikes. The sidewalk with residential houses will have trees in the middle to be the separator of semi-private and public realms. The other sidewalk will be rather smaller to enhance the interaction of user with the woodland trees. The final kind of street is the ones inside all of the islands. These streets are going to be available for small level of traffic with only 2 lanes. The sidewalk will be a combination of basic and the one with tree in front of setbacks.
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STREETS’ PROFILES
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Community Space Key Urban Space Urban Space
42 URBAN SPACE STRATEGY
Urban space is another major point of our strategy. Within every “island”, there will be another “island” of urban spaces that are available for sport activities, schools or social infrastrucutre. These spaces are formed based on the topography of the location. The houses along these spaces are curved along the topographic lines to act as an emphasis to the concept, breaking the geometry of the blocks’ grid. A series of urban spaces availble for events and large scale pubic activities are placed along the canal. They are situated at key location to either provide the best access to the wetland and interaction with the water; or as an intimate larger scale space for a neighborhood lack of qualitative open space. This is also used to activate the riverfront as well as the massive productive landscape scenery surrounding the site. To go further into smaller scale, a massive amount of collective community spaces are used everywhere on the site. Either as sequences of bigger ones or setbacks of a few housed within a block, these spaces are most utilized because of the lifestyle of Vietnamese people among their neighborhood. A more intimate and closer space is always appreciated and used better in Vietnam context.
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46 HOUSING TYPOLOGIES
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CONCEPT DIAGRAM 1
50 ZOOM IN MAP 1
FROM THE MAIN ROADS TO THE RIVERFRONT
zoom-in 1 urban design
The first zoom in is chosen to express the implementation of sequences of collective community space that leads the inner activities of the site towards the riverfront and vice versa. It is situated at the intersection of the two most important roads of the area, one going from the city center all the way to Petro Vietnam, and the other one runs along the Ca Mau river. As key mobility structures and commercial spines, the building blocks are larger with height of 7 - 8 stories, and facade follow the perimeter of the blocks. The zoom in was designed as an example of the strategy of leading the people outwards into the riverbank. The streetscape is opened up as wide as possible without damaging the quality of building fronts through the use of open ground floor. Behind the building
AERIAL MAP OF EXISTING MAP 1
blocks are sequences of community spaces that open up to the roads in between buildings to act as leading spaces to the larger scale urban spaces along the river. Another aspect of the zoom in is to illustrate the connection between two large urban spaces, one being on the canal and the other one beside the river. The method stays the same with all pedestrian path out of the canal space leading back to the main road coming towards the river, thus strengthening the function of the road.
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SECTION/PERSPECTIVE 1
52 ELEVATION
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CONCEPT DIAGRAM 2
56 ZOOM IN MAP 2
COLLECTIVE SPACES SEQUENCE TO LANSCAPE
zoom-in 2 urban design
The second strategic zoom-in map is chosen to illustrate the connection between the geometric break urban space and the linear open space along the canal that open up the view towards the massive productive landscape scenery bordering the area. Again, the usage of sequences of collective community spaces is applied to act as stepping stones towards the canal park. The design also expresses the structure of a geometric break block. Since the space is specifically dedicated to urban activities and social infrastructure, bigger and longer building blocks are curved along the topographic lines of the location. Opening in between builidngs are selected as the best connection between the inner space and the sequenced spaces. Diverse urban experience
AERIAL MAP OF EXISTING CONDITION 2
is also a focus of structuring this zoom-in design. From the curved urban space to the community ones to the canal park, buildings are placed to create a shifts in volume of open spaces. This would allow various kinds of urban activities to take place with more emphasis on larger one and the ones in between are transitional.
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SECTION/PERSPECTIVE 2
58 ELEVATION
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CONCEPT DIAGRAM 3
62 ZOOM IN MAP 3
CANALSCAPE - URBAN BLOCKS - RIVERFRONT
zoom-in 3 urban design
The third zoom-in is chosen to illustrate the connection between another geometric break block and the riverfront. The same principles apply for the inner urban space: larger, longer buildings are used, curved along the topographic lines of the location and dedicated to social and sporting activities. The housing structure on this site is bound by the usage of distribution space. The urban spaces are covered by dwellings to provide access toward the back as well as a collective community space for the neighborhood. Together with small openings in between buildings, they form a sequence of spaces that ultimately lead users from one large urban space to another. For outsider of the
AERIAL MAP OF EXISTING CONDITION 3
area, the connection between the two spaces are also available via the pedestrian path placed along the canal. The zoom-in is also to express the opening point of the canal to the river. Through the leading boardwalk and urban spaces, the river and the canal combine to create a quality riverfront neighborhood that carry on the landscape quality of the canal into the riverfront, together an entity of urban spaces.
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SECTION/PERSPECITVE 3
64 ELEVATION
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CONCEPT DIAGRAM 4
68 ZOOM IN MAP 4
FROM COLLECTIVE SET-BACKS TO URBAN FOREST
zoom-in 4 urban design
The fourth and last zoom-in is chosen to illutrate the shift between the dense housing blocks into the the blocks among the forest. The density of the dwellings decline towards the canal and the woodland to create a softer edge for the “island�.
the house as possible. A distance is always maintained between the houses and the trees to provide access and open space for quality living standards.
Inside the dense blocks, the houses are formed along the periphery of the blocks with occassional setbacks to create intimate and qualitative collective spaces for the neighborhood. The typologies are 4 - 5-story high to adapt with the existing condition. Into the houses in the woodland, the housing types are rather the same with the difference is the usage of duplex on the first and second floor to allow as much of natural lighting for
AERIAL MAP OF EXISTING CONDITION 4
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SECTION/PERSPECITVE 4
70 ELEVATION
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CLUSTERIZATION DEFINES THE BETTER CA MAU
conclusions
As a trend throughout the whole nation of Vietnam, being a metropolitan is the aim of all the cities. Heavy infrastructure and massive centric densification are used everywhere as the tool for faster and fancier development. Ca Mau has been one among the many to be doing so. And in the long term, this would not be sustainable as flooding and saline intrusion has come to be very big issues of the region. By separating the development into “islands� and having them framed along the river and the main roads, the city as well as the whole region will be relieved of the issues they are facing. With the amount of built surface, the city will definitely reach to be the city it wants to be, but in a more integrated manners that would allow all of what Ca Mau is to define what it should be.
The city is filled with water, and living with water should be the way to do it. Rather than running away from it by raising new ground higher and let the older one suffer from the flooding, it should be that the water is smartly into the city, bring the floating market, the water buses, the beautiful wetland landscape and all that is identity to Ca Mau.
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