The valleys south of the Atlas
An ecosystem on the verge of sustainability
Jordi Badia Pascual
Faculty of Surveyors and Technical Architects of Barcelona – CAATB
Center for The Study and Recovery of the Kasbas of Southern Morocco – CERKAS
1997 – 1998
From: Organic Waste Recycling
In 1876, a German chemist, Justus von Liebig, studying the agricultural history of North Africa was transposed by the fate of this region and the implications it had for its time. During the first century d.D., the fertile lands of North Africa supplied two-thirds of the cereals they consumed in one city: Rome. The nutrients, however, and the organic matter contained in these foods did not return to North Africa, rather than being dumped into the Mediterranean. In the mid-3rd century, this flow of nutrients leaving the cereal lands of North Africa on a road of no return, along with the fall in organic matter levels contributed to the development of the Sahara desert.
The State of the World of 1998. Worldwatch Institute. – Chapter 6 – by Gary Gardner (Page 107)
Abstract:
The valleys south of the Atlas, an ecosystem on the verge of sustainability. The main feature of my contributions was in the sustainability factors, including the architectural and urban bioclimatism of Kasba as a whole, to the description of the almost isolated ecosystem of the oasis type, where the water that arrives from the River Dráa towards the Sahara desert is wisely used in orchards near the villages, and this fully anthropized ecosystem only exists in a range of 100 or 200 meters next to the river route. And the Berber and Tuaregue villages are appearing every few kilometers following this pattern of subsistence.
1 The natural history of the region
The regional ecosystem south of the Atlas is the stone desert. 99% of the region is arid, without water and without a layer of fertile soil, in addition, without land, since wind and torrential rains are responsible for sweeping the sland and sand that are generated from the intemperity of the rocks.
Archaeological discoveries show us a maghreb much greener than the current one. The savannah covered mountains and plains as it is currently found in the sub-Saharan area. Gazelles, giraffes, predatory big cats, as well as a diverse vegetation: Cedars, Acacia… in fact, there is speculation in a continuous savannah for Mali and Ghana What happened to all this natural wealth?.
Photo 1. Rock gravels south of the Atlas
History repeats itself: The Roman Chronicles speak of the great "trade", that is, the exploitation of these riches, between the shores of the Mediterranean. The trees were cut down and the wood was exported to the rich Roman citizens: Cedar, pine, juniper, etc… First were the herbivores: antelopes, deer, deer, zebras, etc… to feed the starving armies of peacekeeping.
So it was the turn of the carnivores: the lion, and the tiger despised for competing in the hunt for the increasingly scarce herbivores, and appreciated to show their skins and for the circus spectacles of the imperial city, which included the fight with elephants (where did they come from?) – A party at the Roman Colosseum could mean slaughtering hundreds of wild animals a day for a hundred days in a row .
The ecological footprint of the great metropolis Rome was overwhelming, and Carthage, its imperial rival was in Africa itself… The ecosystem has been irreversibly decimated. The dispute over Africa's riches led hannibal's elephants to cross the strait and the Alps.
The story continued with an increasingly poor and fragile scenario, currently only isolated strongholds of cedar forests in the Mediterranean Atlas, and some fragile acacia trees forgotten in the dry beds of the torrents that descend from the Atlas.
Map 1. The rivers of Hammada
Without the structure of the roots provided by the trees, and without the contributions of fertilization of animal waste, the ecosystem was truncated. The rainfall and temperature regime was, and still is, too hard for the upper sun to withstand the avalanches of melted water followed by the torrid summer sun.
From there, the Maghreb sank in the night of time. The unconscious action of the city man away from the places from which natural riches are extracted ended with most natural ecosystems. Currently the most Mediterranean area of the Maghreb are large areas of cereals or cork oak plantations, all with a very low yield.
South of the great mountain range there is virtually nothing left, a desert. Even now it's hard to explain what's between Atlas and the Air.
Photo 2. Torrent descending from atlas
The life of the ancestral tribes, scattered in the territory, without problems of density or supply of water or food, was changed in a few years. The tribes were forced to settle around fertile areas and develop a rigid nomadic dynamic through the desert wells. Social and natural history were intrinsically linked to the High Middle Ages. From there, it will not be possible for human communities to develop unless they are close to agricultural land, and these are reduced to an insignificant percentage of the territory between the Atlas and the Saara a few tens of meters alongside the rivers.
The rest of the territory is becoming increasingly poor, unanthropized ecosystems have not survived, and the anthropised ones, at a delicate limit of survival – do so with reduced levels of biodiversity.
Photo 3. Alto Atlas Village
The territorial reorganization was extremely harsh and generally fraught with wars for food security. The possession of the territory becomes evident and the human population is the one that divides that territory excluding organisms that are not useful to it. And yet not all tribes will be able to take fertile territory, giving rise to tribal struggles that reach almost our century.
The more peaceful families retreating to the High Atlas, and continued their traditional nomadic grazing life in the Alpine meadows.
The territorial reorganization was extremely harsh and generally fraught with wars for food security. The possession of the territory becomes evident and the human population is the one that divides that territory excluding organisms that are not useful to it. And yet not all tribes will be able to take fertile territory, giving rise to tribal struggles that reach almost our century.
The more peaceful families retreating to the High Atlas, and continued their traditional nomadic grazing life in the Alpine meadows.
The best-adapted families were transformed into farmers appropriating the small valleys and canyons that descend from the Atlas, taking advantage of the first sedimentary backwater that forms at the foot of the mountain range, and the large auvial terraces that follow the rivers before entering the Sahara desert.
But there were still some tribes without fertile territory, who chose the path of looting and plundering, tribes with warrior vocation appeared.
Parallel to the European Middle Ages, a dynamic of terror and protection developed that led to a society of castes, lords and peasants, artisans and slaves.
Over several centuries there was subsistence agriculture, fortification and the sawasntion of nomadic tribes that came from the most punished and inland areas of the desert.
The land and cultivation systems did not supply much of the population, so the villages built were very small. At first they were reduced to large families organized into a single building – fortified housing: the Ksar
Photo 4. Fortified village with Ksar – Ait-Ben-Haddou
In quieter areas where cultivation was abundant, families could group their members into separate dwellings within the same fortification: the Kasba, which was also structured in long labyrinthine corridors rather than streets.
Or the cooperation of different families, different Ksars in the same village so that different neighborhoods were generated for the different castes.
Sometimes, in the poorest areas or those that rarely suffered attacks, it was enough to fortify the community barn.
Photo 5. Orchard with ditch and palm tree
The arrival of Islam from the east and north of the Atlas was a political catalyst enough to overcome the dynamics of the local tribes. Religious and philosophical contributions, as well as the cultural and scientific capacity of the East, introduced a well-evolved agrarian culture, and in particular two factors that have substantially changed the local landscape.
- On the one hand, the sustainable and self-sufficient management of scarce water, through the technique of ditches, it is clear that without water there is no life.
From this vital characteristic, it is interesting to observe how the water points: Wells, Washes and Ditches, are key places in the social relations of the inhabitants..
On the other hand, the cultivation of new species adapted to the rigors of the hot climate, especially the palm tree of the date. Although it was an exogenous species for the place, it is currently the main protagonist. Everything is used for a thousand and one uses. First, the most sought-after fruit in the region, quality marks prices for the whole country. The trunk is used for construction, the sheets for the basket of braids, as well as for cooking fuel. At the same time, its structural function to root the fertile soil of orchards.
An interesting work would be the study of the management of palm trees, how many of them are cut and how many are planted over the course of a year for a family. In addition to proposing the stabilization of new agricultural land in the torrents. based on the retention of the weathered clay of the stones that is currently washed by the rains.
Today, these are two basic pillars by which the populations south of the Atlas subsist.
Socially, Islam meant a series of pilitico-military pacts that established the power of the feudal lords and, over time, caused the transhuman warrior tribes to enter the markets that crossed the desert for commercial exchange with black Africa, carrying all kinds of precious materials and species, including the slave trade, originating the historic camel caravans.
Photo 6. Tombuctoú Route
At the end of the last century and beginning of this century, French colonization ended up providing contact with the rest of the world and the general, albeit forced, pacification among all peoples. To the present day when this contact and this pacification allowed the adventure of the citizens of Western culture in these lands with the mere danger of being assaulted by children hungry for Westernity.
Map two. The routes south of the atlas.
The modern transformation of the caravans has been the rallies across the desert, which effectively destroyed physical and psychologically important elements of traditional cultures, but also provided some exchange and minimal connection of the innermost corners of the desert with the rest of the outside world.
We are currently facing a complex and extremely fragile scenario, as in almost all so-called third world countries, with little development potential
- The scenario with an agricultural system, practically equal to the high Middle Ages and with very limited and delimited natural resources, very little diversified and on the verge of its recharge capacity.
- The socio-religious scenario, belonging to the Islamic pattern. Repeatedly put into crisis by berber and Tureg ancestral Berber cultures.
- The scenario of "International Tourism" linked to French culture that causes, on the one hand, large migratory flows, as throughout Morocco towards Casablanca or Europe, the latter very politically restricted, and local initiatives for adventure tourism, tourism in many cases disrespectful, as is the case of rallies, but which should be taken care of for better use, seeking a zero environmental impact, both socially and ecologically.
Map three. Morocco
2 The ecosystems of the Southern Atlas
Altimetria airplane
The highest peak in the Atlas, the Toubkal reaches 4,165 meters. The Atlas Mountain Range is an alpine formation similar to the Betica mountain range of the Iberian Peninsula.
The Plains of the High Atlas, at 2,500 meters. above sea level suffer thermal variations of up to 50 ºC between summer and winter, and with it the agricultural possibilities are restricted to some types of crops. On the other hand, herds of goats and sheep enjoy large alpine pastures.
Map four. Atlantic, Mediterranean, Atlas, Saara
The rainy season is quite characteristic, and there is clearly the rainy season in early summer.
Also in late spring the torrents descend floods due to the melting of the high peaks of the Atlas. And both have so much entity about overflowing the torrents and rivers, overtaking the fords and cutting off the roads leaving the villages or the entire region isolated for several days.
Map five. Average annual rad. daily solar
South of the Atlas in this unattributeable region, halfway between snow and the desert, solar radiation levels are impressive.
Measurements at the 31st North Latitude in Oarzazate, the administrative capital, reached highs of 7,800 kwh/m² in June and lows of 3,600 kwh/m² in December. (In Barcelona we are above 1,600 kwh/m² and in Paris at 1,100 kwh/m²) With an annual average of 3,400 hours of sunshine.
They are unbeatable features for a solar energy development program, both photovoltaic and sanitary water.In fact, even though we are in a country considered in the third world, there are more and more installations of small photovoltaic panels. Minimal installations of a single board, and some obsolete but effective model for this context. Nor should it surprise us that its use is for television and the corresponding satellite dish and thus be able to connect with satellite channels in addition to some small light.
Map 6. Mid-December Rad. daily solar
It is inevitable to remember that a public investment policy in this sector would save a lot of fossil fuel, both fuel for small engines, and palm fuel for the kitchen, introducing solar stoves, thus allowing the use of these for other purposes, specifically the palm tree for agricultural beds or composting.
In the village of Tamnugalt, near Agdz, we reached temperatures, 44.8ºC on unprotected facades to the south and 46.6ºC on the roofs. In the last days of August.
Similarly, relative humidity levels reach unacceptable limits for the human organism below 20%, even reaching 17%.
Photo 7. Todra Gorge
The descending valleys of the Atlas often form narrow gorges dug into the stone. However, in the spaces where water is relocated and the auvias are deposited in the curves, some human settlement appears automatically, and along with it, an intensive cultivation of these allusion terraces. The intricacies allow small communities to subsist and their complicated topography previously allowed very well protected sites in the face of loot and loot.
Photo 8. Goat rabaño in the Todra Gorge
The system works with all these extreme conditions, and among them, the climatic phenomena that introduce the greatest risk of destabilization are precisely the torrential storms of summer, that is, the uncontrolled excess of water.
The scarcest and most valued resource is, at the same time, the most "dangerous", because the system is unable to absorb, or rather, a higher dose than the normal flow of the water cycle in the area.
Photo 9. Orchards at the foot of the Atlas
As the canyons widen and the flat surfaces increase, the orchards grow exuberantly. The microclimate is especially suitable.
– Continuous fertilization with the contributions of the High Atlas.
– Shelter from dry winds from the south.
– Guaranteed water supply.
– Solar radiation restricted by the high side walls.
Crop management is quite independent of the time of year due to latitude close to the tropics.
The valleys at the foot of the Atlas were better air-conditioned and achieved a more profitable environment. These are the best-adapted communities, and the best-placed corners in this region between the Atlas and the South. Places that suffer less climatological rigor. And those who historically remained further away from the southern warrior tribes and therefore with less need for fortification
Further down, descending to the lower plains between the Atlas and the Sahara Desert extends the Hammada, the stone desert.
A region of about 300 km wide that runs along the entire southern slope of the Atlas, that is, about 800 km. and through which only a couple of large rivers flow north-south: the Draa, the Daura with their respective tributaries, the Ziz…, which will disappear submerged or evaporated when trying to enter the sand desert.
99% of the territory is barren, the stone hammada swept by wind and storms, we only find the traces of the old savannah, seeing some twisted acacia that remain at the top of the channels of the dry torrents. In some cases, it maintains an underground watercourse, but this is reduced to a significant but tiny part of the territory.
The swept desert is a vast region where we find only two types of ecosystems:
El natural", which occupies almost the entire territory: properly the Hammada stone next to the sunburned stone, kingdom of scorpions and small herds of goats that travel the arid torrents, climbing the acacia trees in search of the few green leaves left.
The Hamada is an extreme space with no hygienic conditions for most living organisms, thermal jumps day – night and summer – very extreme winter, and a degree of moisture below those that any animal or plant can resist. Unable to develop a living ecosystem beyond a possible bacterial world, small insects and some unrelated reptile.
- The other ecosystem we find is an agricultural system – urban. The Palm Grove, that is, all available fertile area, a negligible percentage in relation to the total territory, but of an incomparable value. It is the wet strip and artificially watered by the ditches and protected by the palm trees.
An artificial ecosystem maintained daily by humans based on moisture and temperature management, through river water and palm shade
This 300 km route from the Atlas to the Saara is the space where the river is the great protagonist and only element capable of generating a rich plant life. It is a large linear oasis parallel to the river.
Photo 10. La Hammada near Zagora
Currently, this river line, and a range of about 50 to 100 meters on each side is completely humanized. It corresponds to the auvial terraces that can irrigate and those that reach allusions of the river. Outside this range there is no vegetation in large masses, only a few dry acacia sums appear coinciding with in the dry bed of some torrent, traces of vegetation of the ancient savannah.
3 The ecosystem of the Draa River
The river plant system is completely manipulated by man's work.
Once the original savannah was extinct, Islam introduced the palm tree of the date, and is currently the predominant species in the region, in fact, the green areas are directly called "El Palmeral", and under the palm forest the orchard is intensely organized.
Photo 11. The Draa River as it passes through tamnugalt
Water management becomes basic and primary. Without the management of water and river wells, the agro-urban ecosystem does not work. The knowledge of the water pipe and the obtaining of water on the edge of the fertile area of the terrace allow human settlement, and this allows cultivation within the fertile terrace next to the river.
The ditches are deviations from a part of the river flow, but without dams, they are only arms like inverted tributaries. Ditch technology is not free, but it follows clear system performance criteria.
Figure 1. Typical section of the Draa River, and aquifer operation
The main factor in the restructuring of the management of the territory, and in particular of the orchards, is the rainy season, not only implies a great erosion of the territory, but also the collapse of the hydrographic basins in the course of the main flow of the river. Besides being the main factor of collapse of clay architecture, in which all villages in the region are built.
The rainy season means that in the months of July, August and September the roads are cut off, orchards flood and roofs collapse in poor conditions, are actually torrential storms, and even then, it is preferable not to retain this water on the river course, since it carries so many particles that would disable the dams in a short time. A good option is to raise Algerians, that is, collect water from the slopes of the mountains just before reaching the main course of the river. Although it is possible that this is organized naturally with the recharge of underground aquifers near the river water pipe.
Figure 2. Typical plant of orchards and settlements along the Draa River.
The ditch pipes circulate parallel to the river, but with a lower slope at almost horizontal levels to be part of the river axis and irrigate the orchards.
The cultivated terraces are between 1 and 15 metres above bed level.
This height is regulated by the distance in which it propagates to irrigation water in a ditch, that is, the surface that must be irrigated by the water it collects from the river. In this way, these slopes of up to 15 meters are reached in some parts, although the normal is an average of 5 to 10 meters high on the cultivated terraces.
Photo 12. The river and the road bordering the plantations.
Often the collection is made from neighboring villages kilometers away, and usually successive channels appear at different heights, that is, there are successive captures, allowing a cultivation area to be crossed by 3 or 4 parallel ditches, which disappear as the water they carry is exhausted.
Evaporation on these irrigated orchard surfaces is controlled by the overabundance of plant levels, in the same orchard we find legumes and low fodder, as well as fruit shrubs such as pomegranate, taller trees such as apple trees or climbers, such as beans, and finally the palm roof that keeps the microclimate filtering the scorching sun and winds channeled through the valley.
Similarly, the losses due to filtration are few because the natural drainage quickly reaches the river water table, or finds the stone strata that emerge a few meters deep, returning the water to the main river course or to the underground current of the same river. And repeating the watering cycle a few miles down into another ditch of draa's course
On the one hand, the management of water and the space of fertile land is scarce and precious, but we found that, on the other hand, the microclimate of the palm tree, as a subspace of the sub-Saharan climate, has a climatic regime that allows up to three and four harvests per year, the plants' growing seasons work very agilely and often the farmers themselves are not aware of the time of year due to the state of the crop, (in Europe we understand a crop from its planting in winter, growth in spring, fruits in summer, etc…) but by the type of crop they are planting or collecting, (so that in summer it is time to plant such seed, in autumn such another is planted, in the other winter), this stressed pace of the garden system is also possible thanks to the fact that the work in the garden is also quite intensive so that drainage is to correct and not lose land by salinization, also counting that the extreme erosion of hamada and the slopes of the Atlas are magnificent contributors of new mineral salts for cultivation.
This contribution of new soils can also be given thanks to the absence of reservoirs, or dams, the system is a continuous flow and the river water inlets must be worked every time the river descends with excessive force and takes the beginning of the walls, is much more reliable in maintaining the ditch than in the organization of a definitive stable system as the dams would be.
Photo 13. Orchards on road to tamnugalt
At the same time, torrential rains provide new minerals that come from the immediate river basin, much closer than the floods of the thaw that descends from the Atlas.
The palm grove ecosystem feeds the entire human population of the area, the balance of agricultural trade with the rest of Morocco and the world is very small. The orchards also feed the animal population: chickens, donkeys of cargo and transport that all families have, and some Horses or Camels. In addition to this animal population of human utility, it is only possible to find some reptiles or some desert foxes that approach the water at risk of their lives
Photo 14. Summer Storm
The palm heart fruit produces almost all kinds of vegetables, from its intense irrigation fodder, legumes, cereals, fruits and vegetables are obtained, in addition to dates, local production star, exportable worldwide. Agricultural waste is already recycled for soil fertilization.
At the same time, in another part of the Kasbah ecosystem, and seemingly far from the orchards, the best contribution of fertility to the orchards is managed. In the kasbah universal transport is the donkey, and it is essential, and from its tons of excrement the family gardens are nourished, even collective deposit areas of manure appear for use in family orchards without this resource.
Manure is clearly a totally unhygienic animal waste full of fertilizer elements for plants. It must go through a process of digestion of bacterial microorganisms that transform this animal residue into nutrients assimilated for plants as fertilizer.
Fortunately, the hot and, above all, dry weather favors this microbial process minimizing time and therefore exposure to infections.
Photo 16. Estiercol reserve in orchards
In addition, the architectural structure of Kasba is already prepared to introduce "composting" systems. In fact, it currently integrates them efficiently and discreetly. And just updating this traditional system would be enough to get a perfect compost. At the same time, planning a community sewerage system would certainly be counterproductive, even if these are obviously measures of "progress" from the north and misinterpreted.
Thus, contributions to soil nutrient renewal come in three different ways:
The auvial lands of the Draa River.
- The manure of animals and men.
- Agricultural waste.
Photo 15. The burritos, multi-service fellows.
A decrease in these contributions or the cancellation of one of them would cause irreparable damage to the ecosystem, since it is on the verge of survival, immersed in a geographical region of the desert. A region where the power of the river in the seasons of torrential rains and thaw, added to the sun without protection, devastates everything that is not tied by the roots.
The problems lurking in the South Atlas region are essentially the same ones we encounter in our Western European civilization: poorly designed infrastructure and the hegemony of the car-based progress model.
On the one hand, the construction of dams would deprive the natural contribution of the minerals that water drags from the High Atlas to the oasis of Draa.
And, on the other hand, possibly the introduction of combustion transport that underestimated the need for donkeys would change the palm orchard so much that it would change the entire food system: family self-sufficiency and increased imports of prepared food from Marrakesh through the Atlas Mountains.
These two planning failures in the future of the region would increase the loss of fertile soil, and certainly the import of synthetic fertilizers, etc… and ultimately an ever-increasing cycle of unbalanced changes.
Citation: Recycling of organic waste:
In some regions of the planet the problem lies in the lack of nutrients, [no como en la mayoría de regiones de agricultura industrial, donde el problema grave es el exceso de fertilizantes que acaban siendo contaminantes].
Many African farmers, unable to pay enough fertilizer, are practically mining the soil with nutrients. At worst, nutrients leave agricultural land at a rate three times faster than their restitution. In sub-Saharan Africa in general, fertilizers replace only 28% of nitrogen, 36% of phosphate and 15% of potassium absorbed by crops. The recycling of organic matter could contribute to soil recovery, and in the long run maintain a level of fertilizer use that does not reach the excesses we find in industrialized countries.
The State of the World of 1998. Worldwatch Institute. – Chapter 6 – by Gary Gardner (Page 112)
As I pointed out, the current system works, with all these extreme conditions, although it is not integral or ecologically logical.
The scarcer resource is both critical when an overdose occurs, because the system is unable to control a higher-than-normal water cycle flow in the area. It can wipe out all your natural resources, (except the sun). These are episodes of crisis for the "ecosystem", which is currently recovered thanks to the human work of the ditches, but which in a natural state could lead both to the total desert with the sweeping of the earth, and unlike a slow recovery by not extracting the nutrients that men currently take from the orchards.
4 Urban Settlements
Orthophoto 1. Draa as he passes through Jebel Kisanne
9% of the territory is barren, the stone hammada eroded.
The remaining 1% approximately is the palm grove.
It is the range of plant space, and all this is cultivated, urbanized, "cultivated",
The "urbanized" space is larger than the natural space of the plant, this is reduced to some dry acacia trees in the beds of the torrents. The cultivated vegetable space is fully "urbanized", all fertile terraces are cultivated, all have access to a ditch, and a road, practically all are walled with clay walls, although the grandparents of the place have it, who still remember having seen the orchards without the partition walls.
It is in the arid area where the villages settle, but unlike the ecosystems we know in the northernmost latitudes, the separation between hammada and palm tree is a clearly marked line a step differentiates us from each other, one is land with vegetation, the other is stone.
There is, however, one characteristic that unites the two spaces: the mineral base. Both the orchards and the flat area of the villages are in a layer of clay sediments, which come from the testimony made by the torrents as they descend from the mountains. This site is the mineral key to all the urban and agricultural development of the site. With clay the historical ksars are built, and with clay the orchard is cultivated.
There's no confusion. the house is placed right on the arid edge of this line, so that it does not occupy the orchard, but that it is as close as possible to the water, and the water pipe. (See chart1)
Photo 17. Aerial view of the top of Jebel Kisanne
Beside this line that partways the plant kingdom from the mineral, were deposited the sediments of clays, which carry the torrents of washing of the stone tops. Thus, the villages, the Kasbas and the orchards are slightly above the building material par excellence. The traditional construction rises based on mud walls of 50 cm or more, and heights of up to 15 m. With horizontal structures of palm trunks, oleander branches, straw, reeds and palm leaves, all provided by the immediate environment of the river.
Photo 18. Tamnugalt border section with orchards
The construction with earth and straw, and palm trunk is fully integrated into the ecosystem, could not be otherwise. Clay in the form of Tapia or adobe is kept structurally cohesive by drying with room temperature and humidity. We know that previously the lands that carried more particles of sand to the base walls and have more mechanical resistance were known, and the land with lime were more impervious to the erosion of the summer rains.
Building a few hundred meters further from the sedimentary terraces would mean building with piedra. Meterial that does not offer the same hygrome characteristics as the earth, as it is much denser and does not regulate the passage of water vapor.
Photo 19. Construction choosing land and techniques
The mortar based on earth and straw is absolutely biodegradable over time if there is a abandonment of the building, while allowing a relatively simple maintenance, repairing the surfaces affected by the rainy season.
At the level of the example cite that among the normal greetings among the inhabitants of the villages of Hammada, is asking about the state of the roof of the house, whether it had leaks and if it needs the help of the neighbor to fix it.
We also know that historically the interior surfaces have been completely adorned with paintings, of which some remains are still preserved in the most precious rooms of the ancient palaces, and especially in the wooden ceilings. We cannot ensure the same for external surfaces, since rain effectively washes the facades every year taking a small layer of land. It is also possible that a good camouflage strategy against possible attacks and strikes has always kept people the color of the earth.
Now the historic villages maintain a texture of clay and stones on the walls not dams, and a soft and smooth texture of clay and straw fibers on the overflowing surfaces, uniformly maintaining the color of the earth.
On the other hand, we know, compared to new buildings that the white color on the walls greatly reduces solar thermal capture, so it is also possible that it has been applied punctually.
There is a special point in the village that usually coincides in the orchards – rocky dividing line, is the point where the ditch is crossed, the point where the city is accessed through one of its doors, and where the thefts are accessed. It is the liveiest point in the city, the damp square, the women's space, the laundry, where it is washed at noon in community with all the women, where the boys are seen passing on the way to the palm tree, where they descend to look for water and where the bride and groom begin to choose.
Once again, water determines important patterns in the functioning of the community.
In this aspect, we find radical changes in the new settlements in relation to historical deployments, given that the appearance of the car, the supply of electricity and piped water are allowing to build in spaces a little more distant and independent of the palmeiro.
Together with the demographic explosion resulting from hygienic improvements, there was a reduction and increase in mortality and birth rates. The introduction of European family standards, reducing the family nucleus, but with occupation of more households, created the need for new housing.
Photo 20. Laundry and ditch at the foot of Tamnugalt
This increase in the number of houses has been generated with very different typologies from historical ones: The technical capacity of the construction in height was lost, which in turn was conditioned by reasons of defense and family volume, and resulted in a smaller house on a total surface, but larger on a horizontal surface, so the rate of land occupation is being very high, as in any European city, but with the aggravating factor that the pace of urbanization (water and energy supply and evacuation) becomes unfeasible for local administration. Being very compact implementations we find the characteristics of isolated urbanization in Europe.
Photo 21. Development in perspective of the historic and new Tamnugalt
We are not talking about slum suburbs or ghettos in unhygienic conditions, fortunately the capacity for self-construction is still preserved, although technologically much more impoverished.
The new localities do not come from forced migration, a city in the interior, since the agricultural space is not separated from the historic city, and therefore the families living in the old Kasbas can program the new deployment. It is a new natural extension of urbanization of the ancient city, only that the holistic capacity to know whether to put itself in the territory depending on its bioclimatic characteristics has been lost.
The possibilities of expansion go through different options, the option that follows the logic exposed so far would be to appropriate the line of territory attached to the banks of the river, the linear city, remember Le Corbusier in Oran. Obviously, this possibility encloses many future possibilities in the ecosystem, such as increasing fertile land, or access to water for the rest of living beings in the environment.
Another possibility would be to occupy the lands behind the ancient villages, but in height, organizing multifamilial dwellings according to the archetypical patterns of ancestral families, distributing only in height to their respective family cells.
Finally, the most appropriate solution is the imaginative rehabilitation of the ancient Kasbas and Ksars so that they can be re-inhabited with all the advantages of traditional bioclimatic and bioconstructed wisdom, with modern urban services, hygienic standards and comfort of contemporary society.
This population growth obviously has much wider repercussions on the level of emigration to the country's capitals or to Europe. Which, in turn, generate enough local economic wealth to support this growth without, for now, provoking "third world" tensions, lack of food, drugs or education. Water management is essential and regular supply does not reach historic urban centers. At the same time, there are no sewage recycling systems for the new deployments, while in the traditional Kasbas it has arrived and dried in manure. That is, they cover their natural needs, such as food or housing, and even some induced needs of easy implementation, such as satellite TELEVISION, with some photovoltaic solar panels. And the "modern" collective needs of the community, such as urban and cultural systems, are increasingly neglected.
5th Tamnugalt
Orthophoto 1. Tamnugalt historical.
The village of Tamnugalt is located at North Latitude 31º – 6º West Longitude and 900 m above sea level.
The theoretical approaches of urban thermodynamics explain how historical settlements are placed exactly in line with the upper level of the palm heart, taking advantage of the circulation by the convection of air, generated to the north by the mountain and the bare stone of the hammada, which when heated by the sun generates rising currents and, consequently, the absorption of fresh and moist air from the palm heart.
In this sense, it is a contradiction the tribal defensive system that generated a great wall facing the palm trees, (it was the only sector through which the invader could arrive hidden), – while the eferential system aimed at the hammada had less entity, and in the successive stages of growth of the city became obsolete -. In fact, the actual measurements led us to the conclusion that actually fresh air does not flow through the village. The wall acts as a barrier to the flow of fresh air.
Figure 2. Bioclimatic section of Tamnugalt
It becomes evident that the most grateful spaces throughout the city are those that open windows directly to the palm tree.
Photo 22. Tamnugalt Façade: Kasba Wall
The urban-climatitic strategy places its emphasis especially on the totally empty stretches of the streets and internal courtyards. The buildings of the historic village of Tamnugalt have between two and three floors, although we find some of the four floors, with heights of 3.5 to 4 m, so that the sections reach 10 or 15 m high. It is that the Sun does not penetrate the ground floors creating very vertical spaces proportionally, forcing upward currents, although the horizontal currents that could come from the orchards are not very favored.
Map 9. Access and streets to historic Tamnugalt.
| Streets | Doors to neighborhoods | Roads to orchards | |||
| Tamnugalt Gates | Modern accesses | Ditch |
Boundary between fertile and urban land, around the walls
Map 10. Neighborhoods, buildings and public spaces.
| Lavadeiro, outdoor square | Community buildings | Historic neighborhoods | |||
| Interior central square | Cemetery | Gardens |
In the case of Tamnugalt, in particular, the more extensive streets are oriented parallel to the palm tree, since the city extends parallel to the east and is governed from the central square, instead of being formalized, for example, in comb of orchards.
Photo 23. Tamnugalt Historic + New urbanization
The orientation of the streets is East-West and therefore implies minimal sunlight without being completely covered. While a street that starts from palm grove would be oriented north-south and should be covered by force.
On the other hand, in the light observations of solar routes, at different points of the city we observed curiously how public spaces fulfilled a similar characteristic, without being designed by a higher organism, but are a residual product of individual construction, were oriented east. That is, only in the morning they received direct sunlight. This reduces the lag of the thermal inertia of the interior set, since the walls reissue in the afternoon, instead of at night if they were capturing the West.
The East is also the orientation of the valley that comes from the desert, which is contradicted by a ventilation opening that must be precisely for the West. But, as we mentioned, they are public spaces resulting from the negative of private spaces. From which we can deduce that the West is the position where the private building is placed for a correct capture of the atlas air.
The tribal conception of intimacy and military control has created a very specific type of access to the city, based on a door and a covered and generally narrow space that makes this contact with the plant microenvironment of the river very difficult.
Photo 25. Half-covered street
Once inside the village we find two types of public spaces, the square and the street, diametrically opposed:
The square is an open and empty space where only community activities could be carried out that require a large area, such as the market.
The street, on the other hand, is a narrow space, with tall and relatively cool facades, where children play quietly. The stretch of streets is radically thin to prevent the sun from reaching the bottom, with widths of 2 or 3 m at most, the walls rise up to 10 or 15 meters in the most normal cases
The public space, however, is completely residual as urban value of the community organization, it is the negative of the house, which if it is primordial and organize the space, from the moment when the public space can be covered by one or more pieces of a house that decided to cross the street on the first or second level, always with the approval of the community. The urban degrowth system is coherent from a bioclimatic point of view, as it allows horizontal ventilation at ground level, but prevents sunlight from the latter. in fact, it is the creation of buried spaces typical of desert climates, onlythat and diified in stone suelo.
Photo 26. Small patio of light inside a Kasba
Against this factor we find another ancestral cultural residue, the streets lead from the main square or from the city door to the houses, but they do not propose to communicate the city with each other, one neighborhood with another, the communication routes are strictly like trees and branches that fork but end in a dead end, which effectively hinders cross ventilation through the village.
In relation to the trees, it is worth mentioning that not a single one is found within the city enclosure, the soil is pure stone and the community has never managed a public space with trees because it needs the care of the land and water supply for this possible urban vegetation.
The main element for the bioclimatic management of Tamnugalt are the interior courtyards of the Ksars due to their extreme slenderness, avoiding the insolation of the Ground Floor.
In them the family life is developed, and it is the space where almost all the rooms of the house roll over.
The courtyard is not just a vertical hole in the building. In the old buildings is formed by perimeter galleries on all floors creating a whole space of exchange between the empty courtyard and the private rooms.
Photo 27. Large inner courtyard of the former kasba palace
The proportions of the Kasbas are really slender, with structural lights corresponding to the resistances of the palm tree, which usually do not exceed 3 meters, we have floor heights of 3.5 to 4 m with what happens that for two or three floors high we have 7 to 12 meters, which can reach 15 or 16 for Kasbas with four floors.
And all built with raw earth.
The patios can have very different dimensions depending on the function and representativeness of these, and we can find small ventilation skylights of 0.8 m wide, up to large central courtyards, from the Kasbas belonging to the highest varieties, with dimensions of 10 m or more of façade.
Modern buildings, on the other hand, are not larger than one floor, so the interior sunlight is much larger. In fact, they seem to have lost the building technology of the great historical Ksars based on the raw clay wall. And with it all bioclimatic knowledge and natural bioconstruction. Currently cement is mixed to make blocks similar to adobe, but that is more economically expensive. Moreover, according to recent studies, the rapid scenario at such high temperatures, water evaporation and scarce technical control lead to a very poor and completely unsustainable quality.
The thermal deficiencies and the hygrometric behavior of the new materials are compensated based on surface treatments with tiles and white colors, which prevent the capture of energy from the walls and facilitate the condensation of the snowfall, taking advantage of the effect of evapotranspiration, for subsequent evaporation by refreshing the air, so that when returning to a state of steam absorbs energy subtracting it from the environment.
Photo 28. Tamnugalt with Jebel Kisanne in the background
Jordi Badia Pascual
July 1998
Index
Chapter 1: The natural history of the region
Photo 1 Graveled rocks south of the Atlas
Photo 2 Torrent coming down the Atlas
Photo 3 High Atlas Village
Photo 4 Fortified village with Ksar
Photo 5 Orchard with ditch and palm tree
Photo 6 The Timbuktu Route
Map 1 E. 1: 500,000 The rivers of Hammada.
Map 2 E. 1: 30,000,000 The routes of the Saara.
Map three. And. 1: 1,000,000 The Mediterranean, the Atlantic, the Maghreb, the Saara, the Highs.
Chapter 2: The Ecosystems of the Southern Atlas
Photo 7 Dades Gorge
Photo 8 Herd of goats in the Gorge of Todra
Photo 9 Orchards at the foot of the Atlas
Photo 10 La Hammada near Zagora
Map 4 E. 1: 800,000 Altimetry.
Map 5 E. 1: 800,000 Rains.
Map 6. And 1: 2,500,000 Average annual solar radiation daily.
Map 7 E. 1: 2,500,000 December average solar radiation daily.
Chapter 3 The Draa River Ecosystem
Photo 11 The Draa River as it passes through Tamnugalt
Photo 12 The Draa River and the road that borders the ditches and cultivated terraces
Photo 13 Orchards on the road to Tamnugalt
Photo 14 Summer Storm
Photo 15 The burritos, multi-service companions.
Photo 16 Manure reserve in orchards
Figure 1 Typical section of the Draa River. With palm grove terraces, water pipe and Ksar
Figure 2 Typical plant of orchards and settlements along the Draa River
Chapter 4 Urban Settlements
Photo 17 Aerial view from the top of Jebel Kissane
Photo 18 Tamnugalt border section with orchards
Photo 19. Construction quality by choosing land
Photo 20 Laundry and ditch at the foot of Tamnuglt
Photo 21 Perspective of development of the historic and new Tamnugalt
Map 8 E. 1: 150,000 Draa as he passes Jebel Kisanne.
Chapter 5 Tamnugalt
Photo 22 Tamnugalt façade by the wall of the Kasba
Photo 23 Aerial perspective of the tamnugalt history and the new deployment.
Photo 24 Old Town Square.
Photo 25 Semi-covered Street.
Photo 26 Small courtyard of light inside a Kasba
Photo 27 Large inner courtyard of a Kasba palace
Photo 28 Tamnugalt with Jebel Kissan in the background
Map 9 E. 1: 2,500 Accesses and streets of historic Tamnugalt.
Map 10 E. 1: 2,500 neighborhoods, buildings and public spaces
Figure 3 Section of the Tamnugalt Valley with Jebel Kissane and the Draa River, Operation of air by convection.