The Xiamen Symposium on Marine Environmental Sciences (XMAS 2025)

The research on the coordinated development level of coastal eco-environmental complex systems, based on the concept of land-sea coordination, plays a pivotal role in promoting the resolution of eco-environmental issues in coastal areas, achieving sustainable social and economic development in these regions, and strengthening the construction of marine ecological civilization. In this study, we construct an indicator system for the complex eco-environmental system in Jiaozhou Bay (JZB) coastal zone, China, comprising six sub-systems and thirty indicators. The comprehensive development level and coupling coordination degree model are employed in this study to analyze the indicator system of the complex eco-environmental system in the JZB coastal zone from 1980 to 2020, aiming to elucidate the mechanisms underlying improvements in this complex system. The findings indicate that (1) the comprehensive development level evaluation of the eco-environmental complex system in the coastal zone of JZB exhibits a two-stage pattern: a declining trend from 1980 to 2005, followed by a rising trend from 2005 to 2020. In 2020, the evaluation values for both the A socio-economic subsystem and E JZB ecological subsystem are higher compared to those in 1980. Conversely, the evaluation values for B pollutant discharge subsystem, C hydro-meteorological subsystem, D JZB geographical subsystem, and F JZB environmental subsystem are lower in 2020 than in 1980. (2) The coupling coordination relationship (CCR) of the complex eco-environmental system in the coastal zone of JZB can be categorized into two stages: from 1980 to 2005, the CCR declined from intermediate coordination to slight incoordination. From 2005 to 2020, the coupling coordination degree increased from slight incoordination to primary coordination. (3) In the future, enhancing the comprehensive development level and improving coupling and coordination can be achieved through transforming traditional marine industries, upgrading land and sea sewage systems, implementing strict reclamation controls, and enhancing laws and regulations.

Land-sea coordination,Coastal zone,Pollution effects,Environmental impact,Eco-environmental complex system,Coupling coordination degree,Jiaozhou Bay