Abhatoo - Centre Nationale de Documentation

The springs of water in the bed of Oued Essaquia Elhamra object of our study, were chosen to illustrate impacts of entropic activities on the physico-chemical quality of these waters of springs. The analysis of the situation concerning spring, shows a rather important potential in quantity of water.However, the physico-chemical quality of the water is very low, characterized by very high mineralization and constituents at this state a source of degradation of the immediate environment, furthermore the results of the physico-chemical parameters indicators of pollution : COD (chemical oxygen demand), BOD5 (biochemical oxygen demand over 5 days), dissolved oxygen (DO), nitrate (NO3), nitrite (NO2), ammonium (NH4+), Kjeldahl nitrogen NTK,phosphates (total PT and orthophosphate PO4 2-), etc. stipulate that the waters in thesesources are exposed to heavy pollution expressed by those parameters that exceed standards. In the absence of polluting industry in the city of Laayoune; it appears that this pollution is mainly due to domestic wastes, washing stations, hospitals and, climatic agents onsedimentary rocks is responsible for high concentrations of certain chemical elements such (Cl-, SO4 2-, B, Ca2+... ).The principal component analysis (PCA) was performed using average values for each parameter, results reveal the existence of a relatively marked temporal variation of these descriptors, showing four different stations in groups according to their physico-chemical quality and the level of contamination by sewage discharges.