The Environmental Systems Modelling Platform (EnSym) to Assess Effects of Land Use Changes on Groundwater Recharge

This paper describes an application of EnSym (Environmental SystemsModelling Platform) to assess the impacts of climate change on the groundwater levels in Victoria. EnSym is a modular and user-friendly software platform to facilitate the use of environmental modelling tools. It enables easy and rapid evaluation of environmental outcomes due to changes in land management and climatic conditions. It contains a number of toolboxes that deal with different aspects of the environment including land based biophysical process, groundwater dynamics, spatial and contextual connectivity, and finally, a set of tools for systematic spatial and temporal reporting. In this paper, we apply the biophysical modelling (BioSym) toolbox of EnSym to estimate the amount of recharge to the Victorian groundwater system for specified land use scenarios. The groundwater recharge obtained from BioSym forms the transient inflow to the groundwater system. The modular three dimensional finite difference ground water flow model (MODFLOW) is used to simulate the response of the groundwater system to the transient recharge. We report results of simulating climate change (with a focus on lower rainfall) and its impact on groundwater levels and storage over time. The results can be used as a catchment planning tool, a research tool or to aid cost-effective decision making when planning for future water resource use.