ECOLOGICAL URBAN DESIGN by Mohamed Owaze Ansari

DESIGN II

ECOLOGICAL URBAN DESIGN

Course Director Dr. Elif Erdine Founding Director Dr. Michael Weinstock Studio tutors Alican Sungur Eleana Polychronaki Abhinav Chaudhary Lorenzo Santelli

Mohamed Owaze Ansari & Felipe Oeyen GROUP 05

Abstract The purpose of this project was to take our understanding of the previously computationally built system by studying the stigmergic behaviour of termites, using python coding developed in the biomimetics seminar; based on which a pavillion was to be designed at the center of the courtyard space adjoining the schoolâ&#x20AC;&#x2122;s workshop areas. The idea was to investigate the mathematic, geometric, material and hierarchical logics to develop a critical view on the relationships between systems design and performance. We started by comprehending the system logic by breaking down into elements & studying the individual behaviour of the attractor & repellor points. After multiple tests, we concluded with the space generating function of repellors & structure generating properties of attractor points, which when guided properly could generate different positive and negative spaces. Hence, a concept was derived for the pavillion design, where space generation was guided by constraints based on human basic body movements, and site and area bounds of 2m x 3m x 4m; and applied to the agent- based system to get the desired form. Further on, the form is rationionalised in terms of structural stability and material required for the global geometry using F.E.A. analysis, light penetrability, volume generation for material requirements, etc. The algorithm for the final form was re structured in order to generate a better outcome based on the observations derived from the previously done analysis. Also, a global strategy for fabrication and assembly was hypothised prior to tests using clay and robotic 3d printing. 3d clay printing was done in parts to understand the feasibility of production using human interaction v.s full robotic automation. The relationship between the geometry and the structural stability/strength of the clay (3d printed) moduleâ&#x20AC;&#x2122; s was analysed using karamba tests. In the end, all these tests and analysis informed the final strategy for the fabrication system which discarded the separate construction, assembly and jointing system. Instead, it focussed on hypothyising a continuous clay printing done with the help of a dynamic 3d printing technique, guided on a metal framed structure, starting from base to top.

Index 1. Introduction 2. Sequence 1 3. S1 Conclusions 4. Sequence 2 5. S2 Conclusions 6. Sequence 3 7. S3 Conclusions 8. Iteration 4 9. Final Conclusion

Stage I : Design Strategy

INTRODUCTION

“About 90% of all natural disasters are water-related. Over the period 1995–2015, floods accounted for 43% of all documented natural disasters, affecting 2.3 billion people, killing 157,000 more and causing US$662 billion in damage.” UN world water report.2019

Floods are a real important problem for the world at the moment, and with the current sea level expected to rise as a consequence of the poles melting due to global warming, flooding is expected to cause even more problems in the following decades and century. The frequency and magnitude of flooding events is expected to increase due to Climate change, and along with this increase in number and magnitude of events, also the number of people affected by floods is expected to increase to around 1.6 billion people in 2050 (UN World Water Development Report 2019). A big number of cities are expected to be flooded in the years to come. This being the situation, it is essential for architects, designers and urbanists to start thinking about new solutions to build resilient buildings and cities that work with the flooding condition, generating strategies to deal with water and to turn the problem into an asset, by combining mariculture with inhabitation.

Source: United Nations World Water Development Report 2019

Hoo PeninsulaÂ´s Historical Background and Current Situation For this project we worked in the Hoo peninsula, located at around 50 km East from London. Hoo peninsula is a piece of land located at a depression and surrounded by the Thames estuary to the North, the Medway estuary to the south and the North Sea to the East. Being at the estuary of two big rivers and next to the sea, there is a high presence of salt marshes and brackish waters in the peninsula. Salt marshes along the River Medway are less likely destructed by the currents than those along the River Thames. Another important characteristic of the area is its tidal condition, with a sea level changing throughout the year and the day. The area is known to have been Source: HOO PENINSULA HISTORIC LANDSCAPE PROJECT populated since before the Roman times, when salt production activities were carried out there. The salt making stopped after the land reclamation process which is believed to have started during the Middle Ages and went on throughout the following centuries. Through that process sea walls were built to avoid the low-lands from flooding. Once the walls had been built, the land could be levelled in order to increase the farmable land in the peninsula. These walls drastically changed the landscape, and degraded the natural habitat of a big number of birds, plants and fish. Nowadays Hoo still keeps its rural and coastal identity, with nearly 50% of its surface area occupied by agricultural land and pastures, 29% by mud flats and salt flats and 7% by industries (Carpenter et. al 2013).

Source: HOO PENINSULA HISTORIC LANDSCAPE PROJECT

Due to its proximity to London and its strategic position close to the sea and in between the Thames and Medway Rivers, Hoo peninsula has been subject to a number of projects throughout its history, some built, other abandoned and other which remain ideas for the time being, like Foster and Partners project for an airport that would terribly damage the peninsula. This project constitutes an opportunity to develop a proposal based on the regeneration of the marshland and the mariculture production, that would reshape this environment to its natural state and bring back some of the species which are disappearing from the area.

ENVIRONMENTAL CONDITIONS In order to better understand the area we drew a series of maps showing the tidal condition on the peninsula now, and how that will change in the following 50 to 100 years. As well as a series of cross-sections trying to understand the different kinds of plants, birds and fish that live in the area and what may become of them in the following decades. And a series of maps depicting the salinity of the water under low-tide and under high-tide. This mapping was very useful to determine the area we wanted to work in as well as to start defining our environmental strategy to address the flooding condition in the area. This Set of Maps shows us the sea level under high tide, depicted in blue, and low tide represented in green. The maps show the highest and lowest tide of the lunar month, and the ring surrounding the map shows the level variation throughout a moon month. In the current situation, we can see that without the sea walls, the lowlands in between Hoo and the Isle of Grain, would be flooded under the high tide, leaving a set of small islands disconnected one from the other.

This second map depicts the expected situation in 50 yearsâ&#x20AC;&#x2122; time, considering a 0,70 metre rise on the current sea level. As well as for the previous map, we can see the high tide level drawn by a blue curve and the low tide level drawn by a green curve. We can see that under high tide, a bigger percentage of the area is covered with water, leaving only a few islands in-between Hoo and the Isle of Grain. The circular graph shows bigger variation between the high and low tide than for the map representing the year 2020.

This set of section drawings shows the flora and fauna currently present in the area, tracing a red dotted line around the endangered species. The sections also represent the high and low tidal levels, as well as the storm surge level, and how these would change in 50 years and in 100 yearsâ&#x20AC;&#x2122; time.

Ecosystem 2020 A

Ecosystem 2070 A

PRECEDENT CASE STUDY The Giving Delta, West 8 + Moffat & Nichol + LSU Coastal Sustainability Studio (2014-ongoing) The Giving Delta is an ongoing project situated in the United States, at the Missisipi River Estuary. The project works with six main strategies detailed as follows: "1. Couple annual river operations with long term adaption 2. Shift from flood controlled to controlled flow 3. Move the mouth of the river inland 4. Inevitable transgression leads to a consolidated delta zone 5. Invest in ports & shipping in a consolidated working delta 6. Link community infrastructure in a resilient and adaptive networkâ&#x20AC;? Source: http://www.west8.com/projects/all/the_giving_delta/ We were particularly interested in the second strategy, which turns the flooding condition from a problem into an asset, as it exploits the productive potential of this wetland zone by using the controlled flooding to continuously deposit nutrients that can be used for mariculture.

Source: West 8 http://www.west8.com/projects/all/the_giving_delta/

ENVIRONMENTAL STRATEGY Topographic Low points Our chosen site is defined by the low lands located between the Isle of grain to the East and Stoke and St. Mary Hoo to the West. These lands constitute the topographic low points of the peninsula, and used to be marshlands connecting the Thames and Medway Rivers, before the land reclamation process. Our aim is to re connect the Thames and Medway estuaries through a system of controlled flooding lands, where we can carry out mariculture production, combined with agriculture and housing.

WATER MANAGEMENT STRATEGY

For our water management strategy we decided to work with a hybrid approach, combining natural and hardengineering solutions. The Thames and Medway rivers are connected through a navigable channel to which a series of secondary channels are plugged. In the connections between the secondary channels and the main channels, we install a series of flood gates, to control the flow and velocity of the water getting into the secondary channels. Each one of these secondary channels nourishes a piece of salt marsh where our mariculture ponds are located. Along the main channel, a series of oyster pits are placed, to mitigate the tidal and flooding impact on the land.

FARMING STRATEGY In order to define our farming strategy, we decided to look at what was currently growing in the area and what could be farmed in order to produce food for the population inhabiting the area. By looking at the area we noticed agriculture had a very important role in the communityâ&#x20AC;&#x2122;s history and production, so we decided to combine mariculture activities with agriculture activities. We chose three different crops, potato, carrot and wheat, and three different aquatic species that could live in brackish water, Mussels, Solea fish, and Mud-crab. We estimated the kilos of each one of these produced per square metre, in order to understand the amount of land needed to feed a 50.000 people population.

HOUSING STRATEGY

Pareto Front for Gen 5 to 9

Hoo area Hitory and current situation mmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm mmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm mmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm mmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm mmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm mmmmmmmmmmmmmmmmmm

For Generations 0 to 9

NETWORK LOGIC

Our network is made out of two types of towers, which we will call Type A and Type B towers. Type A towers are high-rise, high-density towers combining housing and agriculture activities, with a flow control system and a boat dock, allowing them to connect among themselves and with the mainland. These towers are located in the intersections of the primary and secondary channels. Each one of these towers is connected to a variable number of Type B towers, acting as a main node. Type B towers are low-rise, low densisty buildings combining housing, agriculture and mariculture activities. They are located in the salt marshes growing along the secondary channels, and are connected to other Type B towers and to the Type A Towers through walkable paths going along the secondary channels.

OVERALL STRATEGY

By the end of this stage, our overall strategy was then determined. We would join the Medway and Thames rivers through a main navigable channel, that would nourish a set of secondary channels and marshland where we would house our population, and farm crops and aquatic species. This hybrid project would work as a buffer zone to reduce the effects of sea level rise, tidal currents and storm surge while housing 50.000 people by 2120. The position of our main channel would not only reduce the effects of flooding, but also constitute a connection for our clusters that could be used for the transport of people and goods.

Stage II : Design Experiments

FC 1

FC 2

FC3

FC 4

TOWER A Tower logic For the design of our Type A tower, we decided to create a building with two ver tical concrete cores, connecting all our floors, a series of central horizontal concrete slabs where we would grow crops, and a u-shaped housing block enclosing the crops. The geometry of the building is determined by a sliced octagon, with a 6 metres offset generating the housing block. In order to optimize our building, we decided to run some genetic algorithm experiments, using Wallacei x for the Grasshopper plugin running in Rhino. We divided our experiments into two different experiments to determine the proportions and final morphology of our tower.

Simulations Simulation 1

In this first experiment we modified the geometry of our tower, by changing its radius and height, as well as the number of agriculture plates appearing on it. We also introduced a slight tilt of our plates that would impact on the amount of sunlight hitting them. To evaluate the results of the genetic experiment, we used three different fitness objectives. The first one being to maximise the number of square meters generated for housing, the second one corresponding to the maximum surface area of farmable land, and the third and last being to increase the sun exposure of that farmland. After running the algorithm we extracted the fittest individuals for each fitness objective, as well as the one with Average ranking 0 and the one with a relative difference between rankings equal to 0. After looking at these results and their performances, we picked the individual with relative difference equal to 0 and used it as a primitive geometry for our second experiment, slightly increasing its radius.

Simulation 2

In this second experiment we would change the rotation of the agriculture plates, the position of the vertical cores in the building, and a progressive scaling up in the XY plane of our housing and agricultural surface, going from bottom to top. In order to set our algorithm, we evaluated the generated solutions according to four different fitness objectives. The first one being to minimise the Outer skin surface area, the second one to maximise the sun exposure on the farmland, the third one to maximise the distance between the cores, and the fourth one to maximise the housing square metres.

After the experiment we extracted six individuals from the results. Those being, the fittest individual for the minimum outer skin surface area, the fittest individual for farmland sun exposure, two Pareto front solutions, the individual with an average ranking 0 and that one with a relative difference between its fitness objectives equal to 0. To reach our final tower morphology we selected the individual with an average ranking equal to 0 and changed the position of the vertical cores in order to increase their distance.

TOWER B Tower logic

To create our Type B tower, we decided to generate a stepped building, keeping a similar logic to our Type A tower. The base geometry would be an octagon, located at the centre of the building, where our farming activities would take place. Under each one of our octagons we would set a rectangular mariculture pond. These octagons would be surrounded by two housing blocks on the outer edges. The vertical core would be situated at one of the outer edge of the biggest octagon. A wooden skin structure would protect our housing units from the extreme weather conditions.

Simulation

For the optimization of our building, we ran a genetic algorithm experiment, again using Wallacei x for Grasshopper. We changed the morphology of the building by adjusting the radius of our octagons, as well as the factor by which they were scaled. We also adjusted the angle between our lower and higher agricultural plate, and the number of plates constituting our building. For the selection criteria we set 5 fitness objectives, to maximise the sun exposure on the farmland, to maximise the farming and mariculture square metres, to minimise the surface area of the outer skin and to maximise the square metres of housing.

From the results of our genetic experiment, we extracted eight different solutions. Those being, the fittest individual for the maximum sun exposure on farmland, the fittest individual for maximum farmland and mariculture surface area, the fittest individual for minimum outer skin surface area and the fittest individual for maximum housing square metres, as well as two Pareto front solutions, the individual with an average ranking 0 and that one with a relative difference between its fitness objectives equal to 0. To reach our final morphology we selected one of the Pareto front solutions and reparametrized the housing units according to the skin morphology.

To reach our final morphology we selected one of the Pareto front solutions and reparametrized the housing units according to the skin morphology. This model is a standardized version where we set the parameters on how the number and size of our plates would change according to the available footprint in our environment. The placement of these buildings on the environment would change their size in a proportionate way to this base model.

CLUSTER LOGIC

Our clusters are each made out of a single Type A tower and a variable number of Type B Towers. The size of the cluster is determined by the size of the marshland it occupies, and it has a maximum length of 1 kilometre between the Type A tower and the last Type B tower, to avoid longer walks than that between the units and the connection nodes.

Both A and B towers work together to address our Flow control and mariculture strategy, our agriculture strategy and our housing strategy. For the mariculture strategy, the flow of water entering the cluster is controlled by the flood gates located in the Type A towers, whereas the mariculture farming occurs in the Type B towers, with a production that varies according to their footprints. For the agriculture strategy, crops are grown both in the Type A and Type B towers, with a higher number of kilograms being produced by the high-rise towers. For the Housing Strategy, Type A towers have a density of 28 m2 per inhabitant whereas Type B towers have a density of 42 m2 per inhabitant.

Stage III : Design Proposal