Modelling Coastal Vulnerability and Adaptation to Sea Level Rise

Abstract

Coastal regions are highly vulnerable to sea-level rise (SLR) therefore developing and implementing effective adaptation alternatives is crucial for their future development. However, there is uncertainty in the timing, duration, spatial location and extent of SLR and storms. The complexity that arises from climate, coastal systems and their interactions in space and time can easily become overwhelming for decision makers to investigate the aspects of adaptation alternatives thoroughly. Dilemmas confronting decision makers are: how to adapt and when to adapt to SLR? Considering the complexity and dynamic nature of coastal systems interacting and changing over time, this paper introduces a new Spatial Temporal Decision (STD) framework to assess coastal vulnerability, and the adaptation alternatives to SLR. The STM is based upon a combination of: System Dynamics (SD) modelling; Geographical Information Systems (GIS) modelling; and multi-criteria analyses of stakeholders' views using the Analytical Hierarchy Process (AHP). The results of the vulnerability assessment indicate that, at the end of a 100 year simulation period, approximately 6 % of the landscape in the study area will be gradually inundated over time, with 0.5 cm SLR per year. However, this situation dramatically changes with scenarios 2 and 3, which represent 1 cm and 1.5 cm SLR per year. Indeed, the percentage of the vulnerable area leapt to about 34 % for Scenario 2, and 56 % for Scenario 3. Using the information obtained from vulnerability assessments, three stakeholder groups (Politicians, Technical Experts and Residents) were consulted to determine the goal, criteria and adaptation alternatives required for the AHP analysis. Analyses of survey data reveal that across the three stakeholder groups, Effectiveness and Sustainability are the criteria of highest priority.