THE GREEN MACHINE
GREENING THE DESERT
The desert, with a horizon in constant projection, fascinates with its virgin magnificence of its landscapes and the purity of its lines.
Beyond the retinal fascination of this sublime landscape of the absences and the silence, the desert is a territory rich in unexploited resources. Indeed, the influence of the desert on the surface of the globe is considerable; there is about 40 000 000km2 of space left in their vast uncultivated majority.
Seen through the prism of world overpopulation and especially global warming, the territory of the desert has turned out to be a major stake in term of sustainable and human development. Every year, 120 000 km2, a surface equivalent to the surface of Benin, is lost because of the desertification and of the degradation of lands.
These territories could produce 20 million tons of cereal a year.
The fast desertification of these lands ends up with famine and decreases food safety.
It is also a major poverty factor for the whole region, damaging the economic stability of nomadic, farming communities.
Poor land means poor people, political riots and social unrest.
Agriculture represents a fundamental wealth of civilization; when we lose biodiversity, the whole social system goes bankrupt.
In 2007, United Nations decreed the desertification issue as one of the major stakes in the XXIst century. Indeed, territories and desert regions represent more than 40% of today’s earth’s surface, and 60 % of earth meadows are becoming depopulated (see satellite photo NASA / Index of desertification).
The stakes in the Saharan desert are thus regional, but beyond they join a wider logic of global rehabilitation. Fossil fuels, carbon, coal and gases are not the only factors which contribute to climate change. Saharan desert precipitations are low (1 in 100mm) but violent, fed by the thermal shock caused by cold air masses from the ocean blending with hot ones from the desert. Nevertheless evaporation is almost immediate, because water and carbon are bounded to organic material from the Saharan grounds.
When the latter are damaged, they release some carbon which returns to the atmosphere. The desert moves forward only when naked grounds are not covered, even slightly, with plants. Saharan grounds are directly subjected to strong climatic variations, burning hot until dusk and freezing at night until dawn. A simple vegetable litter would temper these ravaging variations on the ground level to modify the microclimate, and thus gives one more large scale to the microclimatic land.
Thanks to the prescription of holistic management and strategic pastures, it is today possible to regenerate dry and semi dry grounds by beginning with the Saharan border and the existing oases. They develop by spreading radial roads around these knots. Given that only 20% of the Saharan surface is a desert of sand, the range of possibilities is widened on this territory. Joining this axis, the mobile oasis GREEN MACHINE is a platform, a nomadic and autonomous agricultural and industrial city of regeneration of the deficient ecosystems and the development of the permaculture.
An arc of protection for the sterile grounds.
The structural slab of the city rose on 4 Crawlers. These machines with caterpillars were designed to carry NASA rockets from the manufacturing plant to the launching pad and can be driven on any ground with a considerable load.
The mobile oasis takes advantage of the hostile elements of the Saharan desert; a powerful sun, the wind and strong thermal amplitude between day-time and night-time temperatures.
The GREEN MACHINE is energetically autonomous.
Better still, it generates some electricity thanks to the solar towers, and produces water in order to irrigate overpassed territories.
In its edge, the Green Machine Oasis is equipped with low-tech systems such as:
* 9 balloons producing 450m3 of daily water from air condensation. Two thirds of it is dedicated to the irrigation of the Sahara.
These balloons are suspended over the agricultural city and have the capacity to collect some drinkable water from the air. Balloons gets steam from the air and liquefies it by condensation, to make it circulate in the cold matt of the vertical pipes to a reservoir placed on the slab. The same balloons are equipped with turbines which generate some renewable energy.
* 9 Solar Towers produce a daily power of 450kw. Indeed, solar energy received in the Saharan desert exceeds 2000 kWh / m ² to 3000 kWh / m ² a year.
A potential which the project exploits is by using these Solar Towers, they channel the air warmed by the sun to activate turbines and produce some electricity.
The difference of temperature in greenhouses at the base of the tower creates a depression at the level of its summit. The hot air at ground level longs to go out by the chimney. When winds meet turbines situated in the feet of the tower they can reach 34 miles per hour, generating a flow of electricity as constant as the period of sunshine of the desert.
* 24 500m2 of the cereal fields, directly transformed in factories dedicated to the Saharan seeding.
* 4 500m2 of the hydroponic agricultural greenhouses that are thriftier in water and in energy.
* 4 700m3 of water tanks
* From breeding farms to livestock that fertilize the earth, inhabitants are feed and the local population are supplemented. The solid and liquid organic waste (after methanation and composting), the fermentable products, and the waste water are recycled in a loop short and local in an artillery with ploughing.
* Housing, schools, community restaurants, places of relaxations and pleasure gardens are included in the city.
* A pond of retention of 50 000m3
The principle of revitalization of lands is simple and has already been experienced: thanks to a very wide reversal of the earth due to the passages of caterpillars of 4 by 4, furrows are formed.
The first pairs of caterpillars allow a first ploughing on which is poured a first contribution of water to move the earth and the crisp rock mixed in the sand.
Then, the back pairs of caterpillars come to inject a mixture of water, natural fertilizer and cereal seeds.
The ground is ready to absorb and to retain the rain whether it is by storing the carbon and by destroying the methane.
On a longer timescale, the biodiversity:
_One year after a field is left uncultivated, it is colonized by seasonal plants that last only for a year. Wildlife is limited to insects and small animals which pass by looking for seeds.
_Five years later, some shrubs and long-lasting herbaceous appear, but most of the plants are still short-lived. We find also termites’ nests and dens dug by the rodents there.
_In ten years the long-lasting weeds begin to expand and real trees grow here and there. The jackal and the hare hide among shrubs. Finally the old field distinguishes itself no more than a strong oasis, and we find any sorts of plants and animals; big and small ones, herbivores, as well as their predators there.
According to Pr. Allan Savory, researcher and developer in holistic techniques, if we could re-green half of the desert borders and the meadows of the world, the carbon preserved in grounds would allow us to return to the environmental state of the preindustrial era.
While feeding the whole humanity.
- State: Etude
- Year: 2014
- City: SAHARA
- Client: PAVILLON MAROCAIN FADA' / BIENNALE DE VENISE 2014
- Team: Yachar Bouhaya Architecte, Ariel Claudet - Tristan Spella Rendering