Surface water sources such as stream, river and lake, despite their abundances, can no longer meet up to the global demand as many of them dry up during the dry season, the condition which has been exacerbated by the climate change challenge. This makes food security encompassing a high quest for potable water from a major part of the sustainable development goals (UN SDG 6 2018). The 2017 World Health Organization (WHO)/United Nations and International Children Emergency Fund (UNICEF) Joint Monitoring Programme (JMP) report shows that about 2.1 billion people of the world inhabitants, most of which are in sub-Saharan Africa, require access to drinking water. Increasing population, industrialization and changing consumption pattern have contributed to the global demand for water (WWAP 2015).
Water is an indispensable resource for human existence and is vital for social and economic growth.
This study indicates that variation in groundwater resource potential across Ibadan situated within the basement complex terrain is mostly influenced by the heterogeneity of subsurface geology which varies rapidly in terms of rock distribution and associated hydrogeological indices. Regions underlain by quartzite/quartz schist rocks present medium-to-high groundwater resource potential, while regions underlain by migmatite and granite gneiss rocks mostly have very low–low groundwater resource potential. The map delineates the study area into very low (6.5%), low (41.0%), medium (38.1%), high and very high (14.4%) groundwater resource potential zones. Weighted, normalized and ranked derived thematic hydrogeological parameters (lineament density, drainage density, coefficient of anisotropy, aquifer thickness, overburden thickness, aquifer resistivity and lithology) were employed to generate groundwater resource potential map. Filtered and enhanced Landsat 8 OLI satellite imagery, quality-checked and inverted VES data, and categorized geological and other ancillary data were analyzed and used to generate lineaments, subsurface geoelectric parameters and other terrain information employed to extract thematic hydrogeological parameters used to characterize the subsurface in terms of groundwater potential. The technique weighted and ranked seven sets of thematic hydrological parameters derived from Landsat 8 OLI satellite imagery, 143 vertical electrical sounding (VES) geophysical data, and geological and topographical data. Multi-criteria decision analysis based on Saaty’s analytical hierarchy processing technique has been used to establish groundwater potential distribution pattern across some highly populated parts of Ibadan metropolis in southwestern Nigeria.
0 kommentar(er)
