NEARCONTROL · NEARshore geological CONTROL on coastal morphodynamics: monitoring and modelling in high-resolution

NEARshore geological CONTROL on coastal morphodynamics: monitoring and modelling in high-resolution

Understanding the fundamental controls and drivers of coastal evolution at event to decadal scales is paramount for successful management of sedimentary coastlines, particularly in the current context of increasing coastal development and the challenges posed by global environmental change. Despite general acceptance that the evolution of coastal systems is intimately linked to the inherited geological framework (i.e. coastal orientation, configuration of bedrock and older sedimentary surfaces, sediment type and supply), its influence on contemporary coastal processes is poorly represented in conceptual models of coastal change and generally disregarded in numerical models used worldwide to predict coastal evolution under sea-level rise (SLR). The poor incorporation of geological controls in coastal models is driven, in part, by a limited quantitative understanding of how the geological framework determines modern coastal evolution and how it relates to hydrodynamic processes and morphologic responses, as well as by difficulties in transforming qualitative geophysical observations into quantitative parameters. Long-held assumptions that simple equilibrium profiles are a suitable representation of the nearshore and that beaches are unrestricted piles of homogenous sediment that respond exclusively to hydrodynamic forcing, have further contributed to the poor incorporation of nearshore geological control in contemporary coastal models. Challenging these oversimplified assumptions about coastal evolution and improving the quantification of geological control is essential to understanding event to decadal scale evolution of sedimentary coastlines and improving our ability to predict future coastal response to environmental, climate and sea-level change. NEARCONTROL focusses on the role and impact of the underlying geological control in the evolution of the nearshore, particularly in response to energetic storm conditions. The overall objective is to develop an approach that integrates high-resolution geophysical surveying and exploratory numerical modelling in order to test the hypothesis that the geological framework exerts the fundamental control on nearshore configuration and evolution. Our results highlight that the underlying geological and stratigraphic surfaces determine the overall shape of the nearshore and, by constraining sediment dynamics and morphological change, their impact in contemporary and future coastal evolution is unavoidable. Understanding these interactions and incorporating the associated uncertainties in coastal modelling frameworks will enhance quantitative and qualitative assessments of future coastal evolution and contribute to improved coastal adaptation to SLR.

Data: CORDIS, © European Union