Estimation of groundwater recharge using GIS and remote sensing :

Abstract

Groundwater is one of the best alternatives that can be used to augment water demand of an area especially those found in arid and semi-arid environments where rainfall is un reliable. However, this cannot sustainably be achieved unless accurate prediction of recharge to the groundwater aquifer is done (Tleane & Ndambuki, 2020). The objectives of this study were to estimate the groundwater recharge with a view of ensuring adequate and sustainable groundwater resources in Kabayongo Catchment, Nakitoma Sub-County, Nakasongola District in Central Uganda and to map groundwater potential recharge zones after considering thematic layers of different factors with significant influence on Groundwater Recharge. For example, rainfall, soil properties, land use and land cover, lithology and topography of the area. The thematic layers were integrated together to generate a GWPZ map by the use of Analytic Hierarchy process (AHP) which was used for weight assignment, and Weighted Index Overlay Analysis in ArcGIS 10.8.2. The rainfall map was generated in ArcGIS 10.8.2 environment using the IWD tool in spatial analysis tools. This map was used to obtain the average annual rainfall of the study area, and the recharge was estimated from Chaturvedi empirical formula (Addisie, 2022). The results showed that about 15% of the average annual rainfall recharges the aquifer to replenish the groundwater resource of the study area.