Clouds as Environment Transformational Tools
Sahel Region, Africa
*Third Place of Re-thinking the Future Sustainability Award 2014 Landscape Concept Category



Leonardo Da Vinci called clouds “bodies without surface [1].” They are seen as entities but they are actually groups of countless tiny particles. Clouds emerge without any omen, drift with winds, and disappear. Consequently, human beings usually perceive clouds as something intangible in the air, but in fact clouds come from the ground. The atmosphere, the composition of the air, the type of land cover, and even the human activity configure the shapes and movements of clouds. We all know that the weather and the clouds critically affect our living environments, but we should also keep in mind that “humankind modifies the weather and climate, whether we know it or not [2]”, as Harry Wexler, the head of meteorological research at the U.S. Weather Bureau, reminded other meteorologists in a 1962 speech.


The aim of this design-research project is to attempt to capture the clouds. The invention of satellites and other modern technologies have enabled us to understand more about the capricious clouds through monitoring and research, but we have not yet fully explored the potential of our understanding of nature. By looking at environmental phenomena and different forces that perturb or correlate with each other, the consequences of weather modification and landscape manipulation might be gradually understood. If clouds come from the ground, maybe the marvels of clouds could be literally “built.“


The project attempts to identify the factors that change clouds, examine the consequences of different actions, and, importantly, to rethink the environmental manipulation and the overall outcomes it would bring. It reveals the possibility that the built environment, the artifact of human beings, could play an active role within the natural system. And, if we can build clouds and storms, do we have sufficient reason to create them? Can we foresee the consequences of our godlike operations on this extremely complicated global climate and the local ecology?








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2. James R. Fleming, “The Climate Engineers,” in Willson Quarterly, Spring 2007 (Washington, D.C.: Woodrow Wilson International Center for Scholars)

1. Hubert Damisch, “The Power of the Continuum,” in A Theory of /Cloud/, trans. Janet Lloyd (Stanford: Stanford University Press, 2002) p.141

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Section, Clouds as water circulation engine.

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Plan, Clouds as water circulation engine.
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A microscopic view of clouds in different heights
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The land cover of Sahel Region
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The clouds over Sahel Region in one day
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The water vapors distribution of Sahel Region
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The anually precipitation of Saherl Region
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The transboundary aquifer distribution of North Africa
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Section of the transboundary aquifer

The design-research project focuses on the Sahel region, which is a grassland belt that stretches from the Atlantic Ocean to the Red Sea, located between the vast, dry Sahara desert and the wet tropical rain forest. Its savannah ecosystem and agriculture activities, the region’s most important industry, depend mainly on the precarious rainfall. Because of this, the Sahel region is permanently threatened by food insecurity and desertification on the south Sahara fringe.

 

In 2011, a meteorologist at the Centre for Ecology & Hydrology, Christopher Taylor, and his colleagues published an article revealing that the patterns of soil moisture in Sahel have a significant correlation with Sahelian storm initiation [1]. Taylor et al. noted, “Evapotranspiration of soil moisture can affect temperature and humidity in the lower atmosphere and thereby the development of convective rainstorms.” The violent sunlight, the rarity of high woods, and the flatness of the landscape allow soil moisture patterns to trigger ground winds that favor the development of convective cumulus cloudsthe cardinal engine that brings water vapors up to the air and forms different kinds of clouds and rainfall. According to Taylor, the probability of convective initiation of storms over Sahel is twice as high above the strong soil moisture gradients than it is above uniform soils.

 

Following the research, another critical inspiration for the project is the essence of the gigantic transboundary fossil aquifer systemone of the world’s largest groundwater systemsthat lies beneath the sandstone stratum covering the Sahara and Sahel. Most of these aquifers were recharged 5,000 years ago when the climate of the area was as wet as a tropical area. The groundwater storage volumes of these areas can be as high as the volume of water of 75 meters depth [2].

 

In this hypothetical project, a new type of pivot irrigation system is proposed to re-activate the water cycle over the Sahel region. Instead of imprudently pumping water up from the aquifer for irrigation in the traditional way, the new pivot irrigation system is a literal “cloud machine” that captures water vapor and triggers the formation of rainstorms. By tracking the patterns of wind, humidity, and temperature and regulating the irrigation time, the system creates drastic gradients of soil moisture pattern. When the sun drives evaporation from an irrigated area with humid soil, a field of unbalanced temperature and humidity is formed. The disequilibrium can catalyze the formation of up currents of air over the hotter and dryer area that suck water vapor from the surrounding lands and transform this into cumulus cloud systems. Their rainfall will eventually balance the manipulated disequilibrium of air and bring the water back to the land again.

 

If the scope is broadened to a regional scale, these artificial patterns of soil moisture not only efficiently utilize the water vapor from the croplands’ evapotranspiration but also capture the moisture brought by the northeast wind from the southern tropical forests, not letting them be blown into the vast and dry Sahara desert. It is a system that initiates a vertical circulation of moisture and water from underground to the air over the dry Sahel region. The cloud-building engine is an environment transformational tool that not only cultivates clouds and crops, but also afforests the endangered fringe between the Sahel region and the Sahara desert.

 

 

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1.  C M Taylor, A Gounou, F Guichard, P P Harris, R J Ellis, F Couvreux, M De Kauwe, “Frequency of Sahelian storm initiation enhanced over mesoscale soil-moisture patterns,” in Nature Geoscience 4, 2011 (London: Nature Publishing Group) p.430-433

2. A M MacDonald, H C Bonsor, B E´ O´ Dochartaigh and R G Taylor, “Quantitative maps of groundwater resources in Africa,” in Environmental Research Letters Volume 7, Number 2 (Bristol: IOP Publishing)

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Experimental model

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Experimental model
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Experimental model
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Experimental model
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Available lands for pivot irrigation system
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The new pivot irrigation system as a "cloud machine"
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Plan of a schemed irrigation pattern for making clouds, small scale
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Plan of a schemed irrigation pattern for making clouds, medium scale
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Plan of a schemed irrigation pattern for making clouds, large scale
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A hypothesised masterplan of the irrigation patterns that can catch the moist air from southern tropical forests
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Cloud making system as an afforestation tool

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an aerial view of the cloud making masterplan
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