continental mapping of groundwater dependent ecosystems: a methodological framework to integrate diverse data and expert opinion

Study region: Australian continent. Study focus: With increasing groundwater development around the world, a method is required to identify and map groundwater dependent ecosystems (GDEs) across broad landscape scales. Identifying the location of GDEs, will ensure that the environmental impacts of increasing water development are understood and will lead to better management of water resources to protect GDEs. In this study, a method is demonstrated that underpinned the development of an online national GDE mapping tool in Australia (GDE Atlas; http://www.bom.gov.au/water/groundwater/gde/map.shtml). Known GDEs and their locations were extrapolated to regional scales using a process that relied on the integration of expert opinion, remote sensing data obtained between 2000 and 2010 and GIS analysis. New hydrological insights: It was identified that 34% of Australia’s landscape potentially contains GDEs of which 5% are classified with a high GDE potential. In addition, new continental scale insights into landscape processes where provided by the derivation and integration of remote sensing products using MODIS and Landsat. These products identify landscapes which are ‘wetter’ or ‘greener’ than surrounding areas, indicating these landscapes are accessing additional water, such as groundwater, supplementary to rainfall. The method reported also demonstrates the importance of expert knowledge, obtained through literature and expert elicitation, in order to provide a conceptual understanding of regional ecohydrological processes to develop rules of GDE dependency that would guide the extrapolation of known GDEs.