Assessment of spatial Variability of groundwater potential and levels: the case of Moroto district, Uganda

Groundwater is a vital resource for mankind and development. However, in Moroto district changes in rainfall pattern coupled with high abstraction arising from population increase have caused groundwater level variations. In this study, the spatial variability of groundwater potential and levels in square area of 3533 km2 was assessed so as to develop maps that will aid decision on site selections for groundwater exploration. The study utilized an integrated technique (remote sensing (RS), Geographic Information System (GIS), Multi Criteria Decision Analysis and geo statistical approach) in analysis and delineation of potential areas for groundwater exploration. The generated map via weighted overlay of thematic layers (slope, soil, lithology, rainfall, land use and land cover) produced five categories of potential zones indicating90 % (15 % very high, 40 % high and 35 % moderate) of the study area to be suitable for groundwater exploration and only 10 % exists as poor potential zones. Further, the analysis of groundwater levels for 189 borehole points using ordinary kinging method indicated Gaussian model as the best fit to understand the variation of groundwater levels. The model was used to generate the groundwater level map that showed variations in groundwater levels across the study area with less than 30 m as shallow wells and above 30 m as deep wells. Maps produced from this study can be used to identify appropriate sites for groundwater exploration thereby minimizing unsuccessful boreholes.