Groundwater Quality in Two Arid Areas of Morocco: Impact of Pollution on Biodiversity and Paleogeographic Implications

The biodiversity and the quality of subterranean waters have been comparatively studied in the Haouz plain near Marrakesh and in the Tafilalet, in south-eastern Morocco. For this purpose, physicochemical and faunistic analyses were carried out on the water of ten wells and springs located in the area of Marrakesh, and in Errachidia area respectively. In the wells of Marrakesh, the average stygobiologic diversity is relatively high in the wells located upstream the dumping from the city where the ground water presents low contents of nitrates and orthophosphates. In contrast, the wells located in the spreading zone of Marrakesh wastewaters are characterized by the scarcity or the absence of stygobitic species; in these latter wells, the water is highly polluted. It is rich in nitrates, nitrites, ammonium, and the conductivity is rather high. In the area of Errachidia the faunistic inventory gathers some ten species, some of which are living in hot springs. The subterranean water is highly mineralised. In t...