Traditional Techniques of Underground Water Catchment in the Algerian Sahara

Abstract

In desert regions, the water constitutes an indispensable supply to every human, animal or vegetable life. In the Algerian Sahara, where underground waters are the main exploitable hydric resources, saharian agriculturists make use of several traditional catchment processes. The first process corresponds to the Ghout technique. It is spread in the sandy dune region (erg) of El Oued. Agriculturists create their palm groves at the center of large concentric basins, dug so that the artificial topographic elevation is brought to one meter or less above the water table. The most usual means to get the water up is still the traditional well (hassi), dug by hand. Its construction and its exploitation do not lead to particular problems, nevertheless, these ordinary wells are badly adapted to reach confined aquifers, especially artesian aquifers. However, well-diggers of Oued Righ took up the challenge, by digging real artesian wells with rudimentary tools. Another original process of underground water catchments that has been well developed in the Sahara is the digging of foggaras. This method takes advantage of natural topographic declivity of the ground and the piezometric surface in order to bring the aquifer waters to the surface. The water flows by simple gravity through sub-horizontal draining galleries that lower upper part crests of underground water tables. The water exploitation Mini-review Article Mebrouk et al.; JSRR, Article no. JSRR.2014.005 1068 by these different techniques is a good example of mastery and rational use of natural resources. Today, in strong competition with modern drillings within great pumping discharges, these techniques are fast disappearing. Nevertheless, through new know-how contribution and by adapting modern techniques, these patterns of catchments can make an important contribution to ensure the durable use of water in these arid regions.