ESTIMATING GROUNDWATER RECHARGE USING AN INTEGRATED SURFACE AND GROUNDWATER MODELING APPROACH

This paper describes the use of an integrated surface and groundwater modelling approach to estimate regional groundwater recharge rates. The daily verison of the Monash Rainfall-Runoff Model, HYDROLOG, was adapted to represent the surface hydrological processes and the finite-element groundwater model, AQUIFEM-N, used to model the groundwater flow. The integrated model was calibrated against streamflow and potentiometric head data, with recharge estimated as an output from the calibrated model. The model was applied to both the irrigated and non-irrigated areas in the northern half of the Campaspe River Basin in north-central Victoria, Australia. The integrated model utilises the important features of the surface and groundwater models. It is useful in evaluating water resource development through better management of the conjunctive use of surface and ground water, and is an important tool in any predictive recharge study.