Climate Change Vulnerability Assessment and Adaptive Capacity of Coastal Wetlands 1 Decision Support Framework – Volume Two
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Climate Change Vulnerability Assessment and Adaptive Capacity of Coastal Wetlands Decision Support Framework – Volume Two Acknowledgements The authors would like to thank the Steering Committee who oversaw the work of this project and provided valuable input: Mark Rodrique, Parks Victoria, Rex Candy, East Gippsland Catchment Management Authority, Eleisha Keogh and Matt Khoury, West Gippsland Catchment Management Authority, Andrew Morrison, Port Phillip and Westernport Catchment Management Authority, Donna Smithyman, Corangamite Catchment Management Authority, Jacinta Hendricks, Glenelg Hopkins Catchment Management Authority, Andrea White and Janet Holmes, DELWP. Andrea White provided comments on the draft and final reports. Authors Heard, S., Treadwell, S. and Boon, P Citation Department of Environment, Land, Water and Planning (2016). Climate change vulnerability and adaptive capacity of coastal wetlands. Decision Support Framework – Volume Two. Department of Environment, Land, Water and Planning, East Melbourne, Victoria. Photo credit Tim Allen © The State of Victoria Department of Environment, Land, Water and Planning 2016 This work is licensed under a Creative Commons Attribution 4.0 International licence. You are free to re-use the work under that licence, on the condition that you credit the State of Victoria as author. The licence does not apply to any images, photographs or branding, including the Victorian Coat of Arms, the Victorian Government logo and the Department of Environment, Land, Water and Planning (DELWP) logo. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/ ISBN 978-1-76047-427-0 (pdf/online) Disclaimer This publication may be of assistance to you but the State of Victoria and its employees do not guarantee that the publication is without flaw of any kind or is wholly appropriate for your particular purposes and therefore disclaims all liability for any error, loss or other consequence which may arise from you relying on any information in this publication. Report produced by Jacobs Group Australia Level 11 452 Flinders Street Melbourne VIC 3000 Web: www.jacobs..com Jacobs Limitation: This report has been prepared on behalf of and for the exclusive use of Jacobs’ Client, and is subject to and issued in connection with the provisions of the agreement between Jacobs and its Client. Jacobs accepts no liability or responsibility whatsoever for or in respect of any use of or reliance upon this report by any third party Accessibility If you would like to receive this publication in an alternative format, please telephone the DELWP Customer Service Centre on 136186, email [email protected], or via the National Relay Service on 133 677 www.relayservice.com.au. This document is also available on the internet at www.delwp.vic.gov.au. Contents 1. Introduction .................................................................................................................................................. 3 1.1 Background ................................................................................................................................................ 3 1.2 Vulnerability assessment framework ...................................................................................................... 3 1.3 Decision Support Framework ................................................................................................................... 3 1.4 Volume Two Report ................................................................................................................................... 4 2. What are coastal wetlands? ....................................................................................................................... 6 2.1 Definition of the term 'coastal' ................................................................................................................. 6 2.2 Definition of the term 'wetland' ................................................................................................................ 6 2.3 What types of wetlands occur in the Victorian coastal zone? .............................................................. 7 2.3.1 Mangroves ............................................................................................................................................... 7 2.3.2 Coastal saltmarsh ................................................................................................................................... 8 2.3.3 Seagrass beds ........................................................................................................................................ 8 2.3.4 Other types of coastal wetland ............................................................................................................. 8 2.3.5 Wetland zonation with elevation and tidal inundation ...................................................................... 11 2.4 Coastal wetlands ..................................................................................................................................... 13 2.4.1 Marine Embayments ............................................................................................................................. 15 2.4.2 Estuarine – intertidal ............................................................................................................................ 15 2.4.3 Estuarine – supratidal ................................................................ .......................................................... 16 2.4.4 Coastal floodplains............................................................................................................................... 17 2.4.5 Dune systems ....................................................................................................................................... 17 2.5 Spatial distribution of coastal wetlands across Victoria ..................................................................... 18 2.5.1 Which is the best spatial dataset to delimit the coastal zone? ....................................................... 18 2.5.2 Which is the best spatial dataset to identify wetlands in the coastal zone?.................................. 18 2.5.3 Applying the EVC database to identify coastal wetlands ................................................................ 20 2.5.4 Coastal wetland mapping .................................................................................................................... 21 3. What is climate change in the coastal context? ..................................................................................... 23 3.1 Components of climate change ............................................................................................................. 23 3.2 Critical climate-change components for coastal wetlands ................................................................. 25 3.2.1 Changes in eustatic sea level and increased storm-surge activity ................................................. 26 3.2.2 Increased carbon dioxide .................................................................................................................... 27 3.2.3 Increased temperature ......................................................................................................................... 28 3.2.4 Changes in rainfall................................................................................................................................ 28 3.2.4 An overview of likely impacts ............................................................................................................. 29 3.3 Climate change projections and scenarios .......................................................................................... 30 3.3.1 Australian climate change projections .............................................................................................. 30 3.3.2 Climate change projection for the Victorian coast ........................................................................... 32 3.3.3 Applying the projections to identify exposure of climate change components to coastal wetlands ......................................................................................................................................................... 34 3.3.4 Mapping of exposure of climate change components to coastal wetlands ................................... 35 4. How will coastal wetlands respond to climate change? ....................................................................... 35 Climate Change Vulnerability Assessment and Adaptive Capacity of Coastal Wetlands 1 Decision Support Framework – Volume Two 4.1 Conceptual models.................................................................................................................................. 37 4.1.1 Sea-level rise and storm surges ......................................................................................................... 37 4.1.2 Carbon dioxide concentrations ........................................................................................................... 43 4.1.3 Temperature .......................................................................................................................................... 45 4.1.4 Rainfall ................................................................................................................................................... 47 4.2 Sensitivity ranking ..................................................................................................................................