Modeling of groundwater recharge using a multiple linear regression (MLR) recharge model developed from geophysical parameters: a case of groundwater resources management

In this paper we developed a simple multiple linear regression (MLR) recharge model that relates the recharge estimates obtained from rainfall to the geophysical parameters obtained from the interpretation of two-dimensional (2D) resistivity imaging data for the purpose of efficient groundwater resources management in the southern part of Perak, Malaysia through recharge rate estimation and prediction. Through application of linear regression model, the estimated recharge from rainfall and the corresponding estimated unsaturated layer resistivity and its thickness (Depth to aquifer top) parameters obtained from geophysical measurements were regressed in R software written code environment for generating a MLR recharge model. The sensitivity of analyzed results of the MLR recharge model based on the parameter estimation of the model predictors (resistivity and depth) evaluated at Pr ≤ 0.05 is 5.39 × 10⁻⁰⁶ and 8.39 × 10⁻⁰⁴, respectively. The accuracy and predictive power test conducted on the developed model using both t test and \( \chi^{2} \) distribution at α = 5 % significance level established the model estimation and prediction capability. The obtained results of \( \chi^{2} \) distribution test and parameters estimation test confirmed the reliability and accuracy of the proposed model in recharge rate estimation and prediction in the area. The application of the MLR recharge model gives estimate of 242.30 mm/year for regional groundwater recharge rate in the area. Through GIS tool, the MLR recharge model was used to produce groundwater recharge rate prediction map. A quick and independent estimate of recharge by simple geophysical measurement has been established based on these results. The information on the prediction map could serve as a scientific basis for groundwater resources management and exploration in the area. The approach suggests a new application of geoelectric parameters in determining recharge rate due to infiltration. The technique provides a good alternative to other methods used for this purpose.