Adapting to climate change: A risk assessment and decision making framework for managing groundwater dependent ecosystems with declining water levels. Supporting Document 7: Spatially representing the impacts of falling groundwater due to climate change on groundwater dependent ecosystems
Author: Simon Neville
This report illustrates a methodology for spatially representing the impacts of falling groundwater due to climate change on groundwater dependent ecosystems was tested on wetlands of the data-rich Gnangara Mound (Gnangara Study Area), the data-poor Blackwood catchment (Blackwood Study Area) and adjacent caves (Jewel and Lake Caves, Margaret River). GIS data was integrated with Bayesian Models to successfully run 3 models in a spacial form: ii)The Gnangara Vegetation Change Model (a broad-scale model that predicts vegetation change in areas where groundwater is less than 5.2m deep), ii) The Gnangara Macro-Invertebrate Model (a site-specific model that predicts risk of change to macro-invertebrate communities and water quality), and iii) The Blackwood River Fish Health Model (developed by analysing groundwater-river level relationships where groundwater has a significant effect on water quality in the summer months). The models listed above dealt with the nature of the event, and the probability of it happening, but did not clearly evaluate consequences. A second stage of the process combined the risk maps with previously produced conservation value maps for the wetlands, to produce consequence maps. These maps provide a simple tool for identifying where wetland assets are under most threat, and where wetlands are most likely to survive under different future climate scenarios.