Adapting to climate change: A risk assessment and decision making framework for managing groundwater dependent ecosystems with declining water levels. Development and case studies
Authors: Jane Chambers, Gaia Nugent, Bea Sommer, Peter Speldewinde, Simon Neville,Stephen Beatty, Stacey Chilcott, Stefan Eberhard, Nicola Mitchell, Frances D’Souza, Olga Barron, Don McFarlane, Michael Braimbridge, Belinda Robson, Paul Close, David Morgan, Adrian Pinder, Ray Froend, Pierre Horwitz, Barbara Cook and Peter Davies
This report describes the development and testing of a risk assessment and decision-making framework for use in managing declining water levels in groundwater dependent ecosystems (GDEs). A major strength of the framework is its capacity to relate climate, hydrology, water quality/biotic resources and ecosystem response in a single tool, thus helping to provide a transparent outline of the cause and effects of change to an ecosystem, and highlighting key drivers that should be the focus for management and climate change adaptation. The framework was tested on three different Australian GDEs. On the wetlands of the Gnangara Groundwater System in Perth, this study investigated the risk to entire wetland ecosystems and to different guilds of amphibians, identifying key drivers that could be used as management targets to determine where and when amphibians may be under stress under different climate change scenarios. At the groundwater intrusion zone of the Blackwood River site, spatial mapping of endemic freshwater fish species illustrated very high levels of risk to fish populations by 2030, but also identified key sites that could provide refuges with appropriate management. At the Leeuwin Naturaliste Ridge Cave System where groundwater levels have been declining, cumulative rainfall departure analysis indicated that the potential extinction of Threatened Ecological Communities (EPBC Act 1999) of stygofauna was more likely to be due to anthropogenic rather than climate impacts, highlighting an intervention opportunity. The approach used in this study can be easily transferred to sites within Australia and internationally. Guidelines for using the framework is outlined in detail in a companion document: Adapting to climate change: a risk assessment and decision making framework for managing groundwater dependent ecosystems with declining water levels: Guidelines for Use.