In-Depth Analysis of Drought Trend in Semiarid Saïs Plateau and Middle Atlas Region in Morocco

Abstract

This study explores the spatiotemporal properties of droughts and their evolution in the semiarid Sa & iuml;s Plateau and the Middle Atlas regions in Morocco. The methodology includes the analysis of 36 years of precipitation data recorded at 16 meteorological stations, the use of the standardized precipitation index (SPI) at different temporal scales of short term (1 and 3 months), medium term (6 months), and long term (12 and 24 months) to capture historical droughts, and the application of the Mann-Kendall test to assess the drought trends. The wet and dry periods in the Sa & iuml;s Plateau and Middle Atlas regions are almost evenly distributed, with 65% in the "near-normal" condition. The "extremely dry" period, with a value of 1%, was lower than the "extremely humid" period (1.65%). There is no topographically and climatically significant difference between the Sa & iuml;s Plateau and the Middle Atlas in terms of droughts, which are found to decrease over time in both regions. The results of Mann-Kendall test reveal that the short-term trends are generally positive, except at the Boulemane station (- 0.06 for SPI-1, - 0.13 for SPI-3). The long-term precipitation increases in the Middle Atlas region, particularly at the Ait Khabach (0.33 for SPI-24) and the Imouzzer (0.36 for SPI-24) stations. On the Sa & iuml;s Plateau, the trends are positive at the stations of Fez City (0.16 for SPI-24) and Dar Elarsa (0.27 for SPI-24). Significant trends are more pronounced at longer time scales.