Holistic coastal protection strategies with nature-based solution for climate change adaptation in deltaic coast

River deltas are the most dynamic landforms on earth and have become more prone to disasters due to climate change and rising sea levels. Sea level rise and other coastal hazards, such as coastal erosion, salinity intrusion, and storm surges, affect delta ecosystems and the livelihoods of people depending on them. Many people live in deltas, with several of them experiencing a growing population, which requires a sustainable and integrated approach to balance various and often competing interests, notably ecosystem conservation, biological and cultural diversity, agricultural productivity and other social and economic benefits to support livelihoods. This study proposed coastal protection strategies for the Mekong delta, including nature-based solutions and permeable breakwaters. Although single coastal protection defences are currently the prevailing practices in the region, their success is limited to slowing down the erosion rate. Due to the complexity of the hydrodynamic and morphological regimes and the characteristic of the mangrove mud coast, one single line of defence is neither sustainable nor successful. Accordingly, this study proposes holistic coastal protection strategies for mangrove muddy coasts under climate change, namely multiple lines of defences incorporating first nature-based solutions and green infrastructure. Second, advanced perforated hollow triangle breakwaters are introduced based on principles of environmental exchange and conservation, such as previously applied to the coastline of Tien Giang province. These breakwaters have shown benefits for wave reduction, as well as for stimulating sedimentation and for restoring mangrove ecosystems. Lastly, holistic coastal protection strategies are proposed for the entire coast of the Mekong delta, with comprehensive coastal protection solutions presented for Ben Tre province