Using Modelling Outputs to Inform Coastal Climate Change Adaptation Studies: Practical Tips for Adaptation Planners and Scientists

Abstract

Understanding, analysing and spatially representing the risk of impacts from future climate change has been a key focus of coastal climate change vulnerability assessments over the past 10 years. These assessments typically rely on deterministic numerical modelling (to varying degrees of complexity and precision) of floodplains and shorelines under future climate scenarios in order to identify potential hazard vulnerability areas for cyclones, tsunamis, erosion, storm tide inundation, overland flooding and for geotechnical hazards such as landslip. Poor interpretation and presentation of outputs means that the use of numerical models in coastal adaptation and management plans can be problematic, both for adaptation practitioners such as land use planners, social planners and ecologists; and for the broader community who, despite being consulted regarding their appropriateness, often have little knowledge of how modelling was applied and how the outputs have been derived. This paper highlights common challenges for interpreting numerical model results, which include not enough information (over-simplification of hazard impacts and effects), too much information (e.g. studies producing a multitude of possible hazard lines), ignoring the real consequences of being within a hazard zone, and poor understanding of the level of confidence associated with defining the hazard area. Using a weight of experience from selected case studies in Australia and the Pacific, this paper provides guidance on more meaningful interpretation of model outputs, for defining hazard vulnerability zones and for enabling more effective decision-making and climate change adaptation planning.