Apport de la télédétection et SIG dans la gestion des hydrosystèmes du sous bassin versant inférieur d’oued Djendjen

Abstract

This research project aims to apply the tools of geographic information systems (GIS) and remote sensing techniques for the rational management of water systems located in the lower catchment basin of river of Djendjen. This is the assessment of water resources and protection of these water systems against environmental hazards: water pollution and soil erosion (silting of the future dam Tabellout). The region, is largely mountainous, shows potential in water, consisting mainly of surface water. The groundwater resources contained in the local rock (fractured aquifers and very small alluvial aquifers( are exploited in the sources or by peasants well. The results show studied the basin has a very high erosive potential that exceeds the tolerable threshold. The developed GIS has allowed us to consider several planning scenarios to reduce this type of erosion and consequently lowering the rate of siltation dam. Among the proposed scenarios, the dense planting system would appear as the most adequate. With regard to water pollution, the approach applied allowed us to map this phenomenon by producing a series of spatial and temporal environmental themes in the form of digital maps. This study shows that the majority of water resources are threatened by pollution from multiple sources (agricultural, urban and natural). The approach applied allowed to reclassify the study area according to a risk scale and according to the administrative division, which gives the possibility to intervene independently on each municipality separately. We conclude that this GIS is therefore an effective tool for planning, management, scenario proposals and decision making, not only for the protection of water resources, but also for environmental management in general.