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

Abstract

Identifying and delineating groundwater-dependent ecosystems(GDEs) is critical in understanding their location, distribution andgroundwater allocation. However, this information is inadequatelyunderstood due to limited available data for most areas where theyoccur. Thus, this study aims to address this gap using remotelysensed, analytical hierarchy process (AHP) andin situdata to identifyand delineate GDEs in the Khakea–Bray transboundary aquifer region.The study tested various spatial-explicit GDE indices that integratesenvironmental factors that predict occurrence of GDEs. These includethe normalized difference vegetation index as a proxy for vegetationproductivity and modified normalized difference water index asproxy for moisture availability, land-use and landcover, topographicalfactors such as slope, topographic wetness index,flow accumulationand curvature.