Delineation of aquifer promising zones and protective capacity for regional groundwater development and sustainability

Abstract

Water security is the central mission of the sustainable development goals. The demand for potable and clean water has skyrocketed due to frequent borehole failures and population expansion, which requires adequate groundwater resource management strategies. Identifying groundwater potential zone, overburden protective index capacity and installations of alternative/artificial storage support mechanisms for water security and sustainability under the growing water challenge and demand is critical. This study identifies; (i) aquifer promising zones (ii) aquifer protective capacity through geophysical investigation and suggests (iii) improving aquifer recovery management strategy as the top three targets for groundwater development. An electric resistivity technique was applied to acquire a total of sixty (60) vertical electrical sounding points with Schlumberger arrays. The study indicates the resistivity layer of the aquifer unit ranges from 21 to 294 Ωm, while the aquifer layer thickness values spread from 8 to 59 m and the overburden thickness overlays the aquifer unit extends from 3 to 20 m. The deeper aquifer zones were encountered between 30 and 59 m, which could be suitable for groundwater development, and the shallow aquifer occurs between 8 and 14 m, which is not encouraging for groundwater development and may be susceptible to surface contaminations. However, for water security and sustainability, multiple boreholes should be sited at the delineated aquifer promising zone where the aquifer is fractured and occurs within a depth of 30 m and above. The weathered/fractured units constitute the regional aquifer units, which are largely responsible for the groundwater potential. The hydraulic conductivity of the regional aquifer was estimated to vary between 0.337 and 10.62 m/day, which invariably enhances the aquifer recovery processing. Groundwater quality and the risk of surface contamination were examined through overburden protective index capacity.

Delineation of Groundwater Potential and the Susceptibility to Surface Contaminants

“…According to [64,55], the resistivity of a fresh basement is a function of its degree of weathering, the fresh basement having resistivities ranging from 1030 Ωm to 9109 Ωm, shows that some parts of the study area are weathered and fractured having resistivity lower less than 1500 Ωm, and this could indicate high aquifer potentials strength. This is because, [64,55] observed that when an area has low basement resistivity values (< 2000 Ωm) is an indication that, the region may have probably been faulted, fractured, or heavily weathered, which could be of great interest to the development of groundwater potential. Interestingly, the low resistivity of the weathered/fractured layer with a high thickness indicates high groundwater potential.…”

“…That is, the high and values usually indicate relatively high thick succession layers and it should be the focus in terms of groundwater potential [49,50,51,52,53,54]. On the other hand, [5,55], noted that the earth most times acts as a natural lter to the in ltrating uid, especially when the earth's subsurface is underlain with an indurated laterite and impermeable clayey, which in turn de nes its ability to resist uid and the degree of its protective capacity [1]. Consequently, the aquifer protective capacity can evaluate from Dar-zarrouk parameters, ( and ), [1,4,56], as:…”

Modification of the Traditional Half Schlumberger Arrays and its Efficiency for Subsurface Exploration

“…Geophysical methods are implemented in a wide range of applications ranging from magnetic, gravity, seismic, electrical resistivity, electromagnetic, induced polarization, radioactive, and so on [4]. However, electrical resistivity surveys remain one of the most efficient and suitable methods for groundwater exploration, especially for depth information [11,12,13]. However, many configurations of electrodes have been designed for electrical resistivity surveys (Vertical electrical sounding), which are occasionally employed in specialized surveys such as mineral and groundwater exploration [7,14,15,16,17,18].…”

Delineation of Aquifer Storage Capacity in Response to Regional Groundwater Development

“…Groundwater is a hidden natural resource and it is very vital to human existence due to its roles in all aspects of life. Frequent borehole failure according to several sources is attributed to the fact that most boreholes and hand-dug wells were not sunk based on good hydrogeological/geophysical information, but are drilled at locations pre-determined by their owners [1,2,3]. Some remarkable studies observed that the roles of groundwater in nation-building cannot be overemphasized [4,5].…”

“…According to [3], more than 30% of the boreholes dug within the complex basement reportedly failed, while the so-called successes were not encouraging due to low yield. In addition, a remarkable study noted that to ensure adequate water security and sustainability, there is a need to install multiple boreholes in geophysical identi ed groundwater promising zones where the aquifer occurs in deeper zones and fractured [3]. This is because most remarkable studies conducted in the complex basement rock noted that the weathered/fractured units are largely responsible for the regional groundwater-bearing capacity [3,11,17,18]These situations therefore make this type of investigation a prima facie for the precise location of fractured zones for productive borehole sites.…”