Erosion and Accretion of a Subaqueous Delta in the Minjiang River Estuary: The Response to Human Activities over the Past 40 Years

Wang, A., Lai, Z., Liang, H., Ye, X., Tao, S., and Cai, F., 2024. Erosion and accretion of a subaqueous delta in the Minjiang River estuary: The response to human activities over the past 40 years. In: Phillips, M.R.; Al-Naemi, S., and Duarte, C.M. (eds.), Coastlines under Global Change: Proceedings from the International Coastal Symposium (ICS) 2024 (Doha, Qatar). Journal of Coastal Research, Special Issue No. 113, pp. 758-762. Charlotte (North Carolina), ISSN 0749-0208. The river delta is a sensitive area of land-ocean interaction and also the area with the most intensive human activities. With further economic and social development, the estuaries have become a key area for development and utilization of resources. This study takes the Minjiang River Estuary in China as the research object, and analyzes the characteristics of erosion and accretion processes of the Minjiang River estuary subaqueous delta over the past 40 years by comparing the water depth data of different periods extracting from nautical charts. The research results indicate that the subaqueous delta of the Minjiang River estuary experiences erosion first, accretion later, and then erosion again since 1983. In terms of spatial scale, overall, nearshore areas exhibit accretion, which gradually transforms into erosion as the distance from the coast increases. In recent years, due to intensive human activities, the sediment flux discharged into the sea by the Minjiang River has gradually decreased, leading to erosion in the subaqueous delta of the Minjiang River. The extraction of marine sand in the estuary area has further intensified the erosion of the subaqueous delta. However, the construction of dyke has led to accretion near the dyke.