Abstract:
This study attempted to delineate and map potential groundwater recharge zones of the
Singida, semi-arid, fractured crystalline basement aquifer using open source remote sensing and
GIS software. Various thematic maps such as lithology/hydrogeology, soil, land-cover/use, slope,
lineament density, drainage density and rainfall distribution were integrated in QGIS software.
Vector input layers were rasterized and resampled using QGIS wrap projection function to make
sure that the grid cells are of the same size. Reclassification using SAGA and GRASS reclass
algorithms in QGIS was carried out to realign the factor classes in a consistent scale, and
reclassification to a scale of 1 to 5 was carried out to harmonize the results. The study identified a
number of potential areas for groundwater recharge, groundwater exploration, groundwater
development and potential areas for artificial groundwater recharge. Potential groundwater
recharge zones for the Singida semi-arid fractured aquifer are restricted to areas with high lineament
density, cultivated areas, grassland and flat to gentle slopes. The potential of groundwater recharge
is also observed in areas with low drainage density. The delineated zones provide a good
understanding of the potential recharge zones, which are a starting point for recharge zone
protection. This blended approach can be utilized for carrying out suitability analysis using the
weighted overlay analysis approach. Areas designated good and very good are recommended for
artificial recharging structures as an alternative technique for enhancing groundwater recharge
through rainwater harvesting. This will help to augment groundwater storage in this semi-arid
environment.
