Low flow and drying up in the basin of the Srou wadi (upstream Oum-Er-Rbia-Morocco) (1976-2019): identification, analysis, and impact ; Étiage et tarissement dans le bassin versant de l’oued de Srou (amont Oum-Er-Rbia-Maroc) (1976-2019) : identification, analyse et impact

Morocco is particularly affected by the problem of water scarcity, due to growing demography, the continuous development of the industrial and agricultural sectors as well as the impact of climate change. However, to properly manage water resources in such a situation, it is essential to know what water is available as well as its different uses, especially during low-flow periods.this thesis deals with the issue of evaluating the water resource available during low water periods in a semi-arid hydro-climatic context, of the Srou river watershed. This basin of the Middle Atlas belongs to the great "water reserve" of Morocco and constitutes the first tributary of the Oum-Er-Rbia river and the Ahmed Elhansali dam. The latter provides water supply for: the Tadla irrigated perimeter, the mining industry (OCP) and drinking water supply. The methodology adopted is based on a geographic method with two hydrological drivers: quantitative hydrology and qualitative hydrology. The data used concerns the hydro-climatic data of the stations of the watershed of the river of Srou (Aval Elhri and Chacha N'mallah) and of the neighbouring stations for the study chronicle 1976 to 2016, i.e. 41 more years of observation. data from the gauging and measurement campaigns of the physical quality of surface water carried out in the area between 2016 and 2019.We proceeded to the recognition of the natural factors which govern the hydrological functioning in the watershed: topography and relief, geology, vegetation, and land use. In the second step, a quantification of the water resources was carried out based on hydro-climatic data from the various stations, this by determining the wet periods and the dry periods during the last four decades. Several indices have been adopted to identify rainfall fluctuations and their impacts on the hydrological functioning of the Srou wadi basin. The third step is devoted to the study of low water levels and dry periods in the basin. We tried to identify the low flow rates using the different ...