Comparative analysis of groundwater recharge estimation Value obtained using empirical methods in Ogun and Oshun river basins

Abstract

Estimation of natural groundwater recharge is a pre-requisite for efficient groundwater resource management especially in regions with large demands for groundwater supplies, where such resources are the key to economic development. Groundwater recharge, by whatever method, is normally subjected to large uncertainties and errors. In this paper, an attempt has been made to derive groundwater recharge from rainfall in Ogun and Oshun River Basin using three empirical formulae which include modified Chaturvedi formula, Krishna Rao and Kumar and Seethapathi. Results from these three empirical formulae were compared using line graph, inter-item correlation and one way analysis of variance (ANOVA). Although correlation coefficients of 0.99-1.0 were obtained which make any of the formula applicable, the Kumar and Seethapathi equation is preferred for preliminary recharge estimation in the basins.

 Keywords: Empirical Formulae; Groundwater Recharge; Ogun River Basin; Oshun River Basin, Inter Item Correlation; ANOVA.