Estimating water yield response to land use in the Namoi catchment of the Murray-Darling Basin, Australia

Abstract

The Namoi catchment is an intensively developed irrigation area in the Murray-Darling Basin (MDB) and has a mixture of land use types including cropping, pasture and forests. It is yet to implement an integrated groundwater and surface water management system. The Soil Water Assessment Tool was applied for the Namoi to estimate surface runoff and groundwater contribution to streams. SWAT estimates showed that the water yield is substantially lower in areas where grazing natural vegetation and plantations are located. Areas where modified pastures and natural and conservation forests are located have generated higher water yield. The variation of water yield in relation to climatic factors and different types of land use can be used to identify areas where water saving can be made through adopting better management practices in an integrated groundwater and surface water management system.