Status: this preprint was under review for the journal HESS but the revision was not accepted.
Adaptation tipping points of urban wetlands under a drying climate
Amar V. V. Nanda1,6,Leah Beesley2,6,Luca Locatelli3,Berry Gersonius4,6,Matthew R. Hipsey5,6,and Anas Ghadouani1,6Amar V. V. Nanda et al.Amar V. V. Nanda1,6,Leah Beesley2,6,Luca Locatelli3,Berry Gersonius4,6,Matthew R. Hipsey5,6,and Anas Ghadouani1,6
1School of Civil, Environmental & Mining Engineering, The University of Western Australia, 35 rling Highway, M015, Perth, Western Australia, 6009, Australia
2Centre of Excellence in Natural Resource Management, The University of Western Australia, P.O. Box 5771, Albany, Western Australia, Australia
3Department of Environmental Engineering, Technical University of Denmark Anker Engelunds Vej 1, 2800 Kgs. Lyngby, Denmark
4UNESCO-IHE, Westvest 7, 2611 AX Delft, the Netherlands
5School of Earth & Environment, The University of Western Australia, 35 Stirling Highway, Perth, Western Australia, 6009, Australia
6Cooperative Research Centre for Water Sensitive Cities (CRCWSC), Clayton, Victoria, Australia
1School of Civil, Environmental & Mining Engineering, The University of Western Australia, 35 rling Highway, M015, Perth, Western Australia, 6009, Australia
2Centre of Excellence in Natural Resource Management, The University of Western Australia, P.O. Box 5771, Albany, Western Australia, Australia
3Department of Environmental Engineering, Technical University of Denmark Anker Engelunds Vej 1, 2800 Kgs. Lyngby, Denmark
4UNESCO-IHE, Westvest 7, 2611 AX Delft, the Netherlands
5School of Earth & Environment, The University of Western Australia, 35 Stirling Highway, Perth, Western Australia, 6009, Australia
6Cooperative Research Centre for Water Sensitive Cities (CRCWSC), Clayton, Victoria, Australia
Received: 24 May 2017 – Discussion started: 16 Jun 2017
Abstract. Urban wetlands experience considerable alteration to their hydrology, which typically contributes to a decline in their overall ecological integrity. Wetland management strategies aim to repair wetland hydrology and attenuate wetland loss associated with climate change. However, decision makers often lack the data needed to support complex social environmental systems models, making it difficult to assess the effectiveness of current or past practices. Adaptation Tipping Points (ATPs) is a method that can be useful in these situations. The method assesses thresholds exceedance of ecological objectives obtained from policy and informs about the effectiveness of the management strategy to the delivery of certain social or environmental goals. Here we trial the method on an urban wetland in a region experiencing a markedly drying climate. ATPs were defined by linking key ecological objectives identified by policy documents to threshold values for water depth. We then used long-term hydrologic data (1978–2012) to assess if and when thresholds were breached. We found that from the mid-1990s declining wetland water depth caused ATPs for the majority of the wetland objectives. We conclude that the wetland management strategy has been ineffective from the mid-1990s when the region's climate dried markedly. Empirical verification of the ATP assessment is required to validate the suitability of the method. However, in general we consider ATPs to be a useful desktop method to assess the suitability of management when rigorous ecological data are lacking.
When anthropological effects result in changes to wetland hydrology; this often leads to a decline in their ecological integrity. We present a policy oriented approach that assesses the suitability of management when rigorous ecological data are lacking. We link ecological objectives from management authorities to threshold values for water depth defined in policy. Results show insufficient water levels for key ecological objectives and we conclude that current policy is ineffective.
When anthropological effects result in changes to wetland hydrology; this often leads to a...