Spatio-temporal Drought Analysis in Arid and Semi-arid Regions: A Case Study from Palestine

Arid and semi-arid regions are generally characterized by water scarcity and low per capita water allocation. This situation is further exacerbated when such areas are agriculturally dominated with high-density residential areas. Faria catchment (320 km(2)), located in the northeastern part of the West Bank, Palestine, is one of these arid to semi-arid catchments where recently, the prolonged drought periods in the catchment and the increasing water demand have made the existing obtainable water resources vulnerable. Catchment drought analysis provides useful information for a sustainable water resources management. In this study, spatial and temporal dimensions of meteorological drought vulnerability in Faria catchment have been investigated using the Standardized Precipitation Index (SPI) as a measure for drought severity. The SPI method was used to detail geographical variations in the drought vulnerability based on frequency and severity of drought events at 1-year time step. This study is applied to rainfall records (1960-2003) for 6 rainfall stations located within the Faria catchment. Magnitude-duration curves are plotted to depict the relationships between drought duration and magnitude. Critical (threshold) drought values were derived spatially to determine the least amount of rainfall required to avoid from drought initiation. Once drought duration and magnitude have been found objectively, it is possible to use this when manage resources for bridging the supply-demand gap to drought affected areas either from alternative water resources or from water stored during wet periods.