Effects of meteorological droughts on water resources in Northern Morocco: Case study of the Martil watershed

Abstract

Recent droughts in the Northern Morocco have highlighted the increasing vulnerability of water resources to this natural hazard, with reduced potential for drinking water supply in the city of Tetouan and its coastal area. Therefore, the main objectives of this work are: the identification of dry events that affected the Martil watershed on the one hand, and the study of the effects of meteorological droughts on water resources on the other hand. For this purpose, a meteorological-hydrological modelling framework was adopted, using standardized precipitation index (SPI) values and the volume of surface water resources recorded at the Torreta station. The results obtained show that the last decade of the 20th century and the beginning of the 21st century have seen the heaviest and most critical droughts in the study area, namely the drought of 1994-95, 1998-99, 2004-05, 2006-07, 2011-12 and 2013-14. Also, water resources have been reduced by 62% to 82% during critical dry years compared to the long-term average for the period 1970-71/2014-15. Finally, this study showed that the rainfall variability is the determining factor in the fluctuations of surface water resources at the Martil watershed because it explains 84% of their total variance.