The morphological evolution and the sustainability of deltas in the 21st Century

Utilising the cellular automata model CAESAR-Lisflood, a novel set of metrics is developed to explore the nature of multidecadal morphological change in delta catchment systems under a range of climatic and environmental change scenarios. Whilst this study has a specific focus on the Mahanadi Delta in India,these scenarios are designed in such a way so as to encapsulate stressors that are common to a broad range of deltaic environments; including increased exposure to meteorological extremes, sediment starvation and eustatic sea-level rise. Compared to terrestrial systems, there have been relatively few studies that focus on the successful simulation of long-term emergent phenomena in coastal catchments, especially in the specific context of deltas. To address this gap, this research aims to enhance our understanding of how emergent processes influence the multidecadal evolution of deltaic environments, and how we can use this information to understand how the system may respond to increasing conditions of climatic stress. This study also seeks to explore how changes in the emergent morphological system may impact certain factors that influence the habitability of the Mahanadi Delta. Through the development of a novel vulnerability index, this study explores: (1) the impacts of an extreme flood event; (2) potential changes in habitat cover; (3) the effectiveness of the model to explore engineering strategies, with a focus on re-naturalising the delta.