Simulated town expansion under ecological constraints: A case study of Zhangbei County, Heibei Province, China

Town expansion changes land-use type, and results in ecological and environmental issues. To minimize the influence of these problems and relieve the conflict between town development and ecological protection, future town expansion should be simulated based on the ecological priority principle. This study systematically designed and analyzed a simulated town expansion under the ecological constraints (EC) scenario in Zhangbei County (2013-2030). The performance of this scenario was assessed by comparing the influence on ecosystem service value with the urban rural master plan (URMP) for Zhangbei County (2013-2030). The results indicate that town expansion under EC scenario has significant advantages over expansion under the URMP scenario; there are large differences in the town expansion areas. In the EC scenario, towns located in higher ecological quality areas had tighter constraints on expansion and only expanded slightly. In addition, most town boundaries in the EC scenario were curvilinear, complex, and soft, which could provide more ecological benefits than the straight, simple, and hard boundaries in the URMP scenario. The spatial evolution trend of the boundaries in the latter scenario tended to lower the comprehensive ecological constraints surface. In addition, in the EC scenario, the influence of town expansion on ecosystem service value was dramatically lower than in the URMP scenario. Town expansion was simulated under the minimum EC scenario, which could provide a new mechanism for allocating construction land based on ecological supply. The results provide reliable information for effectively relieving the conflict between town development and ecological protection and identifying boundary locations for conditional construction areas during regional planning.