Identification and delineation of groundwater-dependent ecosystems (GDEs) in the Khakea–Bray transboundary aquifer region using geospatial techniques

Identifying and delineating groundwater-dependent ecosystems (GDEs) is critical in understanding their location, distribution groundwater allocation. However, this information inadequately understood due to limited available data for most areas where they occur. Thus, study aims address gap using remotely sensed, analytical hierarchy process (AHP) situ identify delineate GDEs the Khakea–Bray transboundary aquifer region. The tested various spatial-explicit GDE indices that integrates environmental factors predict occurrence of GDEs. These include normalized difference vegetation index as a proxy productivity modified water moisture availability, land-use landcover, topographical such slope, topographic wetness index, flow accumulation curvature. were delineated weighted overlay tool Geographic Information System (GIS) environment. thematic output layer was then spatially classified into two classes, namely, non-GDEs. results showed only 1.34% area characterised by covering 721,908 ha. Overall, identified found mostly on gentle slope large portion shrubland grassland. derived map statistically compared with level (GWL) from 22 boreholes occur area. Our indicated that: are concentrated at northern, central south-western part validation significant overlapping classes both rainfall show possible delineation remote sensing GIS techniques along AHP transferable other arid semiarid environments. contributes identifying priority appropriate conservation programmes sustainable development can be implemented.