Contribution of the Catchment Area to the Hydrology of a Saharan Wetland, the Imlili Sebkha (Dakhla Region, Morocco) – Use of GIS and Satellite Data

Abstract

This study concerns a Saharan wetland of southern Morocco, the Imlili Sebkha, located south of the Dakhla city. Considered among the rare permanent saharan sebkhas, it is recharged by episodic surface water supplies from an endorheic hydrographic network and by the unconfined aquifer, which emerges permanently through tens of shallow natural cavities. Using satellite data (DEM and rainfall), supplemented by field observations, an analysis of surface water supplies is carried out in this article. Due to the low slopes and the almost generalized silting of the catchment area, most of the rainwater is evaporated or recovered by the phreatic aquifer. Only a small proportion would arrive to the wetland, which would come from the surroundings of the sebkha. Nevertheless, these low inputs can flood a large part of the wetland, including the groundwater cavities, especially during the biggest autumn storms.