The Effect of Land Use and Climate Change on Groundwater Recharge in Gnangara Groundwater System

Abstract

“Soil-Water-Atmosphere-Plant (SWAP)” model was used to investigate the effect of land use and climate change on groundwater recharge in the Gnangara Groundwater System, Perth, Western Australia. The hydrological and meteorological data (1992-2012) were collected from Bureau of Meteorology and Department of Water, Government of Western Australia. Six different land use scenarios were identified in the spatial map of the area and the results suggest a decline in groundwater recharge under all scenarios. The results revealed that the groundwater recharge is greatly affected by annual rainfall, vegetation and soil hydraulic properties. The rooting depth and leaf area index have significant impact on groundwater recharge. But plant transpiration was found as the major limiting factor for groundwater recharge. Results further showed a non-linear relationship between rainfall and recharge because of non-linearity among other factors such as, weather, soil and crop data.