Resumen
The coastal zone is an area of transition between land and sea, containing rich resources, and it is an important spatial unit where humans engage in production and livelihood. However, in the process of benefiting from the coastal zone, people have neglected the coordinated development of the ecological environment, the economy, and society. To investigate the coordinated development mechanisms of coastal zone systems influenced by human activities, the DEMATEL (Decision making trial and evaluation laboratory) model was applied to identify the key factors influencing a complex coastal zone system. The results were used to construct an indicator system to evaluate the developmental stages of three coastal zone subsystems (ecological environment (EE), society (SOC), and economy (ECO)). The developmental levels of these subsystems over the past ten years were evaluated in five cities along the Yellow Sea coast of China, and the degrees of coupling and coordination among the subsystems were calculated using the coupling coordination degree model. The results showed that during the past decade, the developmental levels of the EE, SOC, and ECO subsystems increased in all five coastal regions, except for Yancheng, where there was a small decrease in the EE level; the coupling degrees of all five regions were high, and the interactions between the EE, SOC, and ECO were very close; the coordination degree was relatively poor. The mean values of Qingdao and Nantong were at an ?Intermediate coordination level?, and the other three cities were at the ?Primary coordination? or ?Barely coordination level?. Three types of interactions between the subsystems emerged: (1) three subsystems have benign interactions and collaboration with each other; (2) the EE, SOC, and ECO compete with each other and have fluctuating upward development; (3) there is a focus on development in the SOC and ECO, and there is a neglect of environmental protection. Based on the development trends of the subsystems and the coupling and coordination laws, some suggestions were proposed.