Analysis of water and soil conservation techniques at the Ain Sefra arid watershed (Ksour Mountains,southwest Algeria)

摘要

In Algeria, the arid steppe watershed currently suffers from serious environmental problems, including land degradation, poor water resource management, soil conservation, and land cover management. This situation is manifested by several events such as soil erosion, depletion of water resources, and loss of biodiversity, which are partly related to the acceleration of the soil degradation process. In order to improve the functioning of ecosystems in these watersheds, public authorities and farmers have undertaken restoration and protection efforts through land-use planning programs. The objective of this study is to test the stability, reliability, and anti-erosion effectiveness of these anti-erosion developments that currently exist on three sites, Sfissifa, Belguered, and Ain Sefra, in the face of the exceptional extreme rainfall events recorded especially in 2007-2008 (250 mm), both on cultivated land and in pasture and forest areas. We found that the traditional techniques generally used by farmers (terraces, stone cordons, toub walls, use of manure, cultivation in tanks and on ridges) have a great positive impact on water and soil conservation at the level of the cultivated plots. In addition, the modern techniques developed by the State (torrential correction, hill retention, reforestation) have proved to be very useful for water and soil conservation on a large scale, i.e., at the level of watersheds. This combination of these two types of development is almost indispensable to ensure a very positive impact on land productivity and the reduction of the risk of degradation.