The optimization of urban ecological infrastructure network based on the changes of county landscape patterns: a typical case study of ecological fragile zone located at Deng Kou (Inner Mongolia)

The ecology of arid area in West China is very fragile. The ecological infrastructure network of county scale is the foundation of urban sustainable development, and of key significance to ensure the stable development of the city in arid areas. Due to the rapid urbanization, Deng Kou County, the typical ecological fragile zone in the west of China, has been chosen as the study region. Thematic Mapper (TM) images in 2000 and 2007, Operational Land Imager (OLI) image in 2014 were selected as main research material. Using the analysis methods of urban boundary shape index, landscape pattern index, landscape transformation network and kernel density mapping, minimum cumulative resistance (MCR) model of ecological sources with different grades are developed and the evolution of urban expansion and county landscape pattern was analyzed. Based on the MCR model, ecological sources are identified and classified. At the same time, the resistance surface is built, and the ecological corridors and ecological nodes are also identified. Moreover, the urban ecological infrastructure network in the county scale was optimized, and the protected area of Deng Kou urban was divided. It is found here, the urban area of Deng Kou expands each year, and the urbanization process was obvious. It is also indicated that the county landscapes, such as poor flow of the landscape and ecology streams, were immensely damaged in 2014. The transformation between urban and construction land, desert shrub land, farmland and desert, determines the characteristics within the whole landscape of Deng Kou County. These kinds of transformation relations are coexisting in terms of 14a scale. The optimizing network of urban ecological infrastructure in county scale in 2014, consists of 391 ecological sources, 47,466 ecological corridors and 799 ecological nodes. Furthermore, the protected areas of urban are divided into 3 zones based on the optimizing network of the ecological infrastructure. The optimizing network of urban ecological infrastructure and the protected areas of urban are constructed for the development of city, which located at the arid area in this study. These constructions would be an important impact on the development and urbanization of Deng Kou County, and contributed to the ecological program for the development of city in the arid areas.