Development of a simplified unsaturated module for providing recharge estimates to saturated groundwater models

Abstract

This paper describes the development of an integrated saturated/unsaturated catchment model of salinity processes and its application to an irrigated and dryland district in northern Victoria, Australia. The model simulates a coupled surface water and groundwater system in which a lumped conceptual model is used to model one-dimensional movement through the unsaturated zone, and a distributed model is used to simulate three-dimensional saturated groundwater flow. Movement of water through the unsaturated zone was found to be dominated by macropore flow, and accordingly the classical matrix flow approximations described by the Richards equation were not used. Instead, a conceptual model of th..