Impact of the development and utilization of coastal areas of Liaodong Bay on the environmental quality of seawater

Through variance decomposition, we investigated the impact of the rate of development and utilization intensity of coastal areas and the economic and industrial structure and spatial location on the environmental quality of seawater. The water quality of coastal waters of Liaodong Bay was evaluated using the comprehensive water quality evaluation index, Nemerow index, and principal component analysis. Dalian and Huludao were found to have significantly better water quality than Panjin, Yingkou, and Jinzhou near the Liaohe Estuary. Marine functional areas and seawater quality index were spatially correlated, and the intensity of sea area development and utilization had a significant positive correlation with the comprehensive evaluation index of seawater quality and Nemerow index. The per capita gross domestic product of coastal cities and seawater quality index followed an “inverted U-shaped” Kuznets curve. Variance decomposition analysis showed that the intensity of sea area development and utilization cumulatively explained 42.3% of the changes in the quality of the seawater environment, while the economic and industrial structure cumulatively explained 31.8%. The direct impact of the intensity of development and utilization of the sea area and the economic and industrial structure contributed 16.5%, while interaction between the natural geographical location and sea area development and utilization intensity and economic and industrial structure cumulatively explained 58.9% of the changes. Our results strongly support management and control of sea reclamation, comprehensive management of coastal waters, and optimization of coastal industrial structure to improve the environmental quality of coastal waters.