Impact study of climate change on water resources in the Tessaout basin (Morocco)

During the last decades, and due to changes of climatic and environmental conditions, water resources available in Morocco are being limited. They are, moreover, subject to extreme cyclical variations and to soaring water demands because of rapid population growth, improvement of living standards, industrial development and expansion of irrigated agriculture. The Oum Er Rbia River feeds much of Morocco's cities; it eventually provides 50% of the drinking water needs of Greater Casablanca (Metropolis and the economic capital of Morocco house four million inhabitants). The pressure on these water resources is accompanied by a growing and increasingly serious degradation of their quality on the action area of ABHOER which strongly sustains the image of other regions of Morocco. This is found at the level of average of air temperatures that are continuously growing and also at the level of precipitation with an average potential of water in the area with a significant decrease since forty years. The purpose of this work is to make a study on the impact of climate change on water resources that exist in the action area of Tessaout , and also to give justifiable results regarding the evolution of climate change by the time unit. The study of the evolution of rainfall recorded since 1935 and the breaks in time series highlighted two methodologically distinct periods: • A wet period with high rainfall (1935 - 1979) • Another dry season and low rainfall (1979 to 1995) Global warming and rainfall regression are added to the intrinsic conditions of Tessaout basin (especially waterproofing of land and the lack of groundwater reservoir) to increase its vulnerability to water scarcity. This critical situation requires adapting good management methods of meteorological water as the only source of water in this basin