Operationalising coastal resilience to flood and erosion hazard: A demonstration for England

Abstract

Resilience is widely seen as an important attribute of coastal systems and, as a concept, is increasingly prominent in policy documents. However, there are conflicting ideas on what constitutes resilience and its operationalisation as an overarching principle of coastal management remains limited. In this paper, we show how resilience to coastal flood and erosion hazard could be measured and applied within policy processes, using England as a case study. We define resilience pragmatically, in economic, environmental and social terms, integrating what is presently a disparate set of policy objectives for coastal areas. Our definition includes several dimensions of resilience and we develop a set of composite indicators for each of these, grounded empirically with reference to national geospatial datasets. A prototype model has been developed, which generates a quantitative resilience index for a given geographical unit (England's coastal hazard zone being represented at a high spatial resolution, about 8,000 areal units). A range of different stakeholder perspectives are captured using relative indicator weightings. The illustrative results presented here demonstrate the practicality of formalising and quantifying resilience, and the insights obtained mainly concern this process of operationalisation. To re-focus national policy around the stated desire of enhancing resilience to coastal flooding and erosion would require firm commitment from government to develop an approach to monitor progress towards resilience, extending the present risk-based approach. This requires a consensus methodology in which stakeholder values are explicitly considered, and also requires incentives for coastal managers to engage with and apply this new approach. Such a transition would challenge existing governance arrangements at national and local levels, requiring more integration and inter-agency cooperation. However, it could provide a robust evidence-based framework for achieving more sustainable, equitable and societally acceptable adaptive responses to climate change at the coast.

Sea Level Rise in Europe: Adaptation Measures and Decision Making Principles

“…One difference between hard and soft measures is their respective impacts on natural sedimentary dynamics and equipment reversibility (Buisson et al, 2012). Soft defence for coastal management includes different types of green, blue, and grey measures.…”

“…Soft defence for coastal management includes different types of green, blue, and grey measures. Examples include the use of geotextile structures as sand containers; the creation of 280 artificial reefs to reduce the wave energy and prevent beach erosion; plant debris cover, windbreaks, and plantations (Buisson et al, 2012). For instance, hydraulic pilings made of wooden rods vertically planted in the sediment at regular intervals, limit sedimentary transport and favour beach stability in pilot studies in France (Buisson et al, 2012).…”

“…Another example of a soft measure is cliff strengthening and stabilisation which includes green and grey options that elements like bolts, tie rods, polymer grids, pinned nets, and rip-rap strips (Buisson et al, 2012). This category of measure is employed in several countries such as Croatia (Omiš) (Oppenheimer et al, 2019), Italy (Marche)…”

“…These types of measures help to reduce erosion and flooding, in addition to providing habitat for numerous species and other environmental benefits for local ecosystems (Barbier et al, 2011). Examples can be found in Spain (Estrategia de Adaptación al Cambio Climático de La Costa Española, 295 2016), Portugal (Programa de Ação Para a Adaptação Às Alterações Climáticas, 2019) and France (Buisson et al, 2012). This latter study shows how France successfully restored marshes and other vegetated ecosystems, protecting against wave energy and therefore limiting erosion and sediment accumulation.…”

“…Providing beach space is beneficial for tourism and recreational activities (Mendes et al, 2021). The objective of this nourishment is to compensate for the littoral imbalance caused by natural erosion and sometimes anthropogenic impact by the presence of defence structures (Buisson et al, 2012). In the literature, the difference between beach nourishment and shore surface nourishment is mainly related to the location of sand 325 placement, which may be respectively on the subaerial beach (above-water beach) or on the subtidal beach (submerged nearshore beach profile) in the form of an underwater mound (Mendes et al, 2021).…”