Vulnerability assessment on human settlement environment of coastal towns with entire-array-polygon method: evidence from Ninghai, China

Rapid urbanization in developing countries is accompanied by changes in the human settlement environment. There is limited research on mixed urban–rural areas with dense population, where new challenges have arisen due to various external and internal factors; therefore, signs of vulnerability are emerging fast. Taking the towns in Ninghai, China as examples, this paper analyzed the vulnerability of human settlement environment in coastal towns of eastern China. Based on the system composition theory of human settlement and the human–environment coupling system vulnerability framework, the key elements and measurement indicators of five vulnerability sub-systems were determined, and the vulnerability assessment system of human settlement environment in Ninghai was constructed. With the entire-array-polygon method, it is found that the overall vulnerability value of each sub-system in Ninghai was in good condition. The paper also revealed that the human settlement environment in Ninghai was mainly restricted by population sub-system, residential sub-system and social sub-system. Specifically, the vulnerability of population sub-system was mainly caused by population size, population growth and population burden, while that of the residential sub-system was mainly caused by the level of settlements, living conditions and green space parks; in addition, the vulnerability of the social sub-system was mainly due to the lack of non-agricultural industries and social security inadequacies. Overall, these findings can serve as a useful reference for local governments to formulate targeted policies to improve the human settlement environment in Ninghai.