A holistic modelling approach to simulate catchment-estuary-coastal system behaviour at macro-time scales

Abstract

Probabilistic assessment of the long-term evolution of inlet-interrupted coasts has always been a challenge, thus continuing to remain a significant knowledge gap. Therefore, this research study was undertaken to gain new insights into the climate change (CC) driven evolution of inlet-interrupted coasts at macro time scales in a probabilistic manner, while giving due consideration to terrestrial and oceanic processes. Here, this was achieved through the development and application of a reduced-complexity (RC) model at a number of locations around the world. Application of this RC model to four sites in USA, UK, Sri Lanka and Australia shows that the long-term evolution of coastlines would vary markedly. These variations are linked to the catchment size, basin surface area and arid/non-arid nature of CC projection. Broader application of the RC model to 41 inlet systems worldwide shows that 93% of the inlet-interrupted coasts will erode under changing climate. The projections also show that the long-term evolution of inlet-interrupted coastlines may not always be governed by the CC-induced sea-level rise, as commonly believed, but may at some locations be governed by the terrestrial processes. Uncertainties in the model projections emphasize the need for probabilistic approaches to investigate the long-term evolution of inlet-interrupted coasts.