Mapping of the Vulnerability to Water Contamination of the Kharroub River Dam (Northern Morocco) by Application of the SW Method

Pollution and contamination pose a permanent risk of limiting water resources. Urbanization and economic development contribute to the degradation of water quality. The preservation of this natural resource is a major necessity, especially in arid and semi-arid areas where surface water is very scarce. This work constitutes part of this environmental concern. It aims at mapping the vulnerability to contamination of the surface water of the Kharroub River dam (Morocco) and protecting its water resources. The method applied is the SW (Surface Water) method, which consists in elaborating thematic maps of three parameters: the hydric functioning of soils, the density of the hydrographic network and the importance of agricultural drainage. The realization and superposition of these maps allowed us to obtain the vulnerability map to surface water contamination of the Kharroub river watershed. The results obtained show that the low and medium vulnerability classes, representing 41.91% and 32.49% respectively, occupy most of the study area and are distributed throughout the basin. The areas presenting a high and a very high degree of vulnerability occupy respectively 24.65% and 0.95% of the surface of the watershed; they are located principally in the northern and the southern parts of the basin.