Drought analysis and groundwater prioritization of a typical data-scarce drought-prone hydrological basin using geospatial techniques

Abstract

The impacts of recurrent drought events have necessitated the spatiotemporal trends analysis of drought and prioritization of groundwater resource in Sokoto-Rima River Basin. Difference Drought Index (DDI) was calculated from downloaded MODIS satellite images in dry seasons within two decadal windows (2000–2018). The index confirmed the trails of droughts in the basin with sub-basins I and IV the worst hit. Morphometric analysis of the basin revealed sixth order and elongated basin type with all the sub-basins flowing in South eastern direction. The favorable geomorphic units for groundwater prospecting can be found in dissected hills, folded mountain, and flood plains. Structural analysis revealed low lineament density and length in sub-basins I and II and high in sub-basins III and IV respectively. Sub-basins IV and I have been ranked as the groundwater deficit and surplus basins respectively using the results obtained from geomorphic, morphometric, and structural analyses. The results obtained from the spatiotemporal trends and sub-basin wise prioritization analyses affirmed that agricultural practices and availability of groundwater resources in sub-basin IV will be at great risk. Conclusively, this study accurately identified areas under groundwater scarcity and these techniques can be applied to any hydrological basin. The regional hydrogeological mapping of aquifers is recommended for further understanding on their vulnerability and resilience to drought events.