Meteorological Drought Assessment in the Ziz Watershed (South East of Morocco)

Abstract

In the face of climate change, drought monitoring and characterisation is indispensable in arid and semi-arid areas. This paper represents a metrological drought assessment in the Ziz watershed located in south-eastern Morocco, through the application of four meteorological indices: rainfall anomaly index (RAI), percentage of normal index (PNI), standardized precipitation index (SPI), z-score index (ZSI). Based on rainfall data series from four stations over a time scale of 37 years (from 1983), also taking into account the relationship between these indices. The analysis of the rainfall series indicates a variability in its spatio-temporal distribution. However, the calculated drought indices indicate that the Ziz basin has experienced drought periods with their different classifications between 1983–2019, noting that the years 1986 and 2001 were dry to extremely dry in all stations of the basin. Thus, the results highlight a strong correlation between the four indices (r ≥ 0.967).