Drought vulnerability modeling over Mandawa watershed, northern Iraq, using GIS-AHP techniques

Abstract

Drought is among the most severe natural calamities induced by lack of water, having a
negative implication on water resources and agriculture in the affected area. Drought types
and severity vary by location, so understanding the spatial distribution can aid in developing
measures to overcome this natural hazard. In this study, the areas vulnerable to droughts in
the Mandawa watershed in the Kurdistan region of Iraq were determined by employing seven
associated factors: rainfall, temperature, LULC, surface slope, soil texture, elevation, and
distance to rivers. Satellite imagery of Landsat 8 OLI for 2021 was employed to create the
Land Use and Land Cover (LULC) and distance to rivers maps. The elevation and surface
slope maps have been generated from the Digital Elevation Model at 30 m resolution, soil
texture map was extracted from The FAO Digital Soil Map of the World and the inverse
distance weighting method was utilized to interpolate the rainfall and temperature
throughout the watershed. Analytical Hierarchy Process (AHP) was used to create a pairwise
compression matrix to obtain the weight of each parameter. In the Geographic Information
System (GIS) environment, the combined impact of affecting factors was utilized to create
the area's drought zonation map. The results indicated that only 5.2% and 13.8% of the
study area is vulnerable to extreme and severe droughts, respectively. While more than 35%
of the watershed is hardly vulnerable to droughts.