Modelling groundwater flow in the North Stirling Land Conservation District, Western Australia

Mathematical models of groundwater flow are beneficial to the management of agricultural systems as they allow the approximation of the components of the hydrological processes and provide a mechanistic description of the flow of water in an aquifer. The flow of water in the North Stirling Land Conservation District (NSLCD), a severely salt-affected area located in south-west Western Australia, is simulated in steady-state and transient using a finite-difference approximation of the two-dimensional partial differential equation for horizontal groundwater flow in an aquifer. Geological, hydrological and climate data are used to generate the input data necessary for the calibration of the steady-state and transient models. The focus in this paper is on the steady-state and transient model calibration and parameterisation procedures and an assessment of the accuracy of results of the model simulations. In particular, the aims of this modelling procedure are to explain both the spatial and temporal variations in groundwater levels across the NSLCD, estimate the groundwater balance components, and assess the effect of land use on the shallow aquifer and agricultural production.