Spatial layout optimization for ecological land based on minimum cumulative resistance model

Abstract: With the urban unlimited expansion, the ecological land excessive reclamation, and the resources and environment deteriorating, the conflict between cultivated land protection, ecological protection and increasing demand of construction land is increasingly intensified. Therefore, there is an urgent need to coordinate the contradiction between socio-economic development and ecological protection by analyzing the key ecological space, the potential for expansion and the policy constraints of farmland protection comprehensively. Coordinating the contradiction between social-economic development and ecological protection also has important significance for regional economy health and stable growth. In this paper, based on the landscape security pattern theory and GIS (geographic information system) technology, 4 critical security patterns including water security, biodiversity protection, disaster control, and landscape recreation were constructed by using the method of ecological space evaluation and landscape security pattern analysis. The method of "adjusted summation" was used to identify the ecological security patterns of the key ecological elements based on the census geographic conditions, land use data and statistical data. With the method of "adjusted summation", the regional ecological security pattern expressed the agglomeration characteristics of multiple ecosystem services in space or time preferably. The resistance for ecological protection was assigned with a value according to the ecosystem service function and ecological value, the economic suitability of construction land and the policy of basic farmland protection. Taking the core ecological land as the protection sources, the minimum cumulative resistance model (MCRM) was used to calculate the minimum cumulative resistance value of ecological land. Ecological protection was graded to 4 zones using the method of natural breaks, namely ecological core zone, ecological control zone, ecological transition zone, and ecological footprint zone. Optimization suggestions were proposed for different zones. Results showed that the core ecological land area in Gaoming District was estimated to be around 301.83 km2, accounting for 32.17% of the study area and 41.33% of the whole ecological land. The zoning result integrating the ecological security pattern, economic potential and farmland protection corresponded to the actual situation and planning objectives in space or time. By analyzing the zoning areas, it could be seen that the area proportions of ecological core zone, ecological control zone, ecological transition zone, and ecological footprint zone were 35.29%, 17.40%, 23.74% and 23.58% respectively. The ecological core zone mainly including rivers and mountains was consistent with the natural and cultural heritage protection area, scenic area, and the planned ecological security control area. The ecological control zone was near the ecological core zone. The ecological footprint zone was mainly distributed in the urban areas in Hecheng Street, Mingcheng Town and a small part of present farmland in Genghe Town. Cultivated land was more than construction land in the ecological transition zone. It is concluded that the ecological core zone and control zone provide important basis for the implementation of ecological space protection. In addition, the ecological transition zone and ecological footprint zone can be used to provide development space for urban expansion and farmland reclamation reasonably.