Evaluating broadscale morphological change in the coastal zone using a logic-based behavioural systems approach

Climate change will have pervasive effects on the world's coasts, but at broad scales these changes have typically proven difficult to analyse in a quantifi- able manner. Consequently, individual management decisions are often taken without consideration of the wider, regional coastal system with its physical linkages between geomorphological elements.

In this chapter, this concern is addressed using an outcome-driven deductive methodology. This provides a qualitative analysis based on geomorphological principles and expert knowledge. A coastal classifi cation, based on generic coastal elements, is used to defi ne the active coastal system with and without coastal management. Potential outcomes (futures) for these elements are then described based on the current understanding of geomorphological processes which are then linked with external drivers using a Driver-Pressure-State-Impact-Response (DPSIR) framework. The uncertainty in future geomorphological change is then described using likelihoods for these possible responses based on individual or consensus expert judgement captured within a simple, transparent matrix.

The methodology provides a whole system level of analysis. It allows different views on system dynamics to be articulated and captured in terms of broadscale patterns of potential geomorphological futures. It is also benefi cial as a precursor to more quantitative models as it provides a framework for interaction between actors with interests in the coastal zone, promoting a more strategic shared understanding of the coastal system. This simplifi cation of the coastal system to key responses and their relationship to external drivers also has advantages for communication with non-experts, promoting confi dence in the decision-making process. The methodology is demonstrated in an analysis of part of the English coastal sediment cell 3 which covers the coastline of Norfolk and Suffolk, on the east coast of the UK.

In terms of the Tyndall Coastal Simulator, this study was used to characterise the broad behaviours of the coastal geomorphic system in the region around our main focus in North Norfolk. The method allows the main geomorphic processes and interactions, which need to be considered quantitatively, to be identifi ed. This stage of assessment, which has often been omitted, is an important step for future studies. The methods used here also link strongly to the wetland and habitat analysis described in Chap. 6.