The impact of climate change on water inflow of the three largest dams in the Beni Mellal-Khenifra region

¹ Faculty of Science and Technology, Sultan Moulay Slimane University, Marroco;
² Higher School of Technology, Sultan Moulay Slimane University, Marroco;
³ Faculty of Science and Technology Sultan Moulay Slimane University, Marroco.

^* Corresponding author: yousrabaq@gmail.com

Abstract

Drought and water scarcity are resulting from the effects of climate change during recent decades. The region of Beni Mellal Khenifra, by the nature of its economic activities based particularly on agriculture and the availability of water resources, is considered among the most vulnerable regions to the effects of climate change in Morocco. In this paper, we analyzed the impact of climate change on the three largest dams in the region (Hassan first, Bin El Ouidane and Ahmed El Hansali), based on statistical data from five stations over 1990-2020. We used Normalized Precipitation Index (SPI) to characterize climatic drought, the Mann-Kendall test to assess the trend of temperature changes, Kendall’s tau and linear regression to detect the relationship between climatic parameters (temperature and precipitation) and water supplies from the three dams. Standardized Precipitation Index (SPI) results showed that the region underwent a significant rainfall deficit between 19911995, 2000-2003, 2005-2008, and 2017-2020. Their intensity varies from moderate to severe type. Moreover, temperature values obtained by Mann– Kendall test showed an increasing trend for all stations. Correlation analysis of rainfall and temperature with inflow dams showed that the mean annual inflows dams are directly proportional to the yearly average SPI increase.