A Review on Methodologies to Upgrade the Coastal Structures to Enhance the Coastal Resilience

As climate change is widespread, rapid, and intensifying, as reported by Intergovernmental Panel on Climate Change, coastal areas are expected to witness a continued increase in sea level throughout the twenty-first century and the future. Further, the intensity and frequency of extreme events are expected to increase in the future. These alarming climate change trends deem immediate engineering intervention to protect the coastline around the world. Coastal defense structures are crucial components in protecting coastal communities and defense-related infrastructures. The existing coastal structures may not be functional to the desired level or become less functional in the future due to climate change and sea-level rise impacts, this might lead to an increase in the wave-induced loads and increased wave overtopping rates resulting in coastal flooding and inundation. Therefore, it is essential to develop methodologies to upgrade and reinforce the coastal structures, thereby making them climate-resilient. There are few efforts taken in the past in this direction, and the present study is aimed to deepen the understanding of the performance of various retrofitting structures in enhancing the resilience against increased wave action. In the present study, we focus on a review of various up-gradation approaches used by various researchers over a wide variety of coastal structures to tackle the climate change impacts and discuss their performance in enhancing coastal resilience. Also, we discussed a new methodology for finding the optimal solution among various alternative methods with an example. This study will help to understand the knowledge gap involved in the existing literature and determine the future research direction towards climate-resilient coastal structures.