Identification of potential sites for rainwater harvesting structures as an adaptation to drought emergencies in Eswatini

Abstract

Water scarcity is a global problem exacerbated by the ever-increasing population and climate change, especially in arid and semi-arid regions. Diferent water resource management strategies, such as rainwater harvesting, have been proposed and implemented worldwide to combat water shortage. Mapping of the optimum sites where these rainwater harvesting structures can be constructed is very important. The main objective of this study was to map and identify, using GIS, optimum sites for the construction of rainwater harvesting structures (farm ponds, check dams and percolation ponds) for agricultural and peri-urban purposes in Eswatini. The optimum sites were identified by overlaying various thematic layers including land use and cover, slope, runof potential, soil texture and depth and drainage density using ArcGIS 10.8. A general rainwater harvesting suitability map was produced for Eswatini, then potential sites for diferent rainwater harvesting structures were identified. The results of the study indicated that all three rainwater harvesting structures have suitable sites where they can be constructed. Check dams have potential sites which cover 22.7% of the suitable area in Eswatini, while farm pond and percolation pond sites covers 19.7% and 65%, respectively. Information on existing structures such as dams and earth dams for water storage may need to be gathered to verify the proposed sites of the rainwater harvesting structures. This study was able to identify new sites where structures can be constructed for rainwater harvesting which can improve water availability during dry seasons. Further evaluation may need to be done before implementation of these structures. Moreover, implementing this is subject to a number of other factors, such as the economy, feasibility studies as well as social implications. However, the results of this study will assist policy and decision makers in planning for potential sites for water storage as an adaptation to drought and climate change.