Abstract

If Morocco is a country with low emissions of greenhouse gases, it remains vulnerable to the impact of climate change due to its geographical position and its dependence on climate-sensitive sectors such as agriculture. By 2050, it is estimated that wheat yield could fall by 7,3 % (IPCC, 2018). The objective of this study is to evaluate the trend of extreme weather events recorded in various Moroccan regions to determine their impact on water resources and agriculture. Five meteorological stations, representative of the different types of climate in Morocco, were the subject of a statistical analysis of the evolution of the indices of extreme temperatures and the daily precipitations over 44 years (1960-2004) and for the four seasons of the year. To predict future projections of these trends, the MAGICC software, coupled with SCENGEN, was used. The temperature trend curves indicate an upward trend in the number of hot days and a strong downward trend in the number of cold days, reflecting a slight warming (1.7 to 2.6 ° C) of the Moroccan climate. As for precipitations, the analysis of the indices retained in our study showed a nonsignificant declining trend (less than 0.05) for the majority of the stations except that of Oujda, where a significant reduction was noted. This downward trend in precipitation (15 to 22% in the north, 9 to 16 % in the south), translates a shift of the semi-arid climate towards the north. The warming of the climate and the decrease in precipitation have resulted in a reduction of 20 % of the inflow of water to dams over 65 years (1940-2005) and by 2050, this reduction could reach 31 %. The result was a significant reduction in irrigated area (7 to 10 %), leading to a potential 15 to 20 % decrease in agricultural production in the north-west region.


Keywords: Extreme weather, temperature, precipitation, projection, water resources, agriculture, Morocco.