Effects of changing climate on the groundwater potential: A case of Chongwe and Rufunsa Districts along the Chongwe River Catchment, Zambia

Abstract

This study assesses the effects of changing climate on the groundwater potential along the Chongwe River Catchment of Chongwe and Rufunsa Districts, through the use of remote sensing (RS) and geographic information systems (GIS). The study area has since the year 2012 experienced water supply shortages, partly attributed to climate change, with the local utility considering the prospects of using groundwater for the area's water supply. The area's groundwater characterisation employed multi-parametric data sets that comprised of remotely sensed data and conventional maps, generated using a weighted overlay approach in geographical information system. A total of 12 general circulation models (GCMs) outputs for precipitation were used for the period 1980 to 2080 as one of the thematic layers for the prediction of the groundwater potential (GWP) zones. The GCMs predicted decreases in precipitation, with the EC-EARTH model being the best performing model in restructuring precipitation with NSE of 0.66 compared with the other 11 GCMs. The spatial-temporal GWP zones showed reductions in zones of high and moderate potential under decreasing rainfall amounts. For continued groundwater availability, the study advocates for optimal allocation of groundwater resources based on the spatial variability of groundwater potential and aquifer yields.