Urban ecological network construction in Loess Plateau regions in China-case study of Huanxian city

Abstract

Cities in ecologically vulnerable areas have high ecological sensitivity, and the balance between urban expansion and the ecological environment is easily broken, leading to various environmental problems. These problems seriously interrupt the sustainable health development of urban ecosystems. Studying urban ecological network construction from the perspective of multifactor ecological processes is of important significance to the ecological safety and resource management of cities. In this study, an analysis of ecological elements was conducted separately to account for the “vertical” and “horizontal” ecological processes present in the ecological network. By using the superposition mode of vertical ecological processes, the composition of vital ecological patches was analyzed, and important ecological patches within the ecosystem were identified through ecological sensitivity evaluation index system. On the other hand, the composition of ecological corridors was analyzed through the use of horizontal ecological processes. The biological corridor was determined by source identification of biological processes and resistance surface analysis while the catchment corridor was determined through runoff simulation. Based on these findings, it was possible to propose an urban ecological network construction system specifically designed for Loess Plateau regions using a superposition of ecological sensitivity, biological processes, and catchment processes. Finally, a case study of the urban ecological network system of Loess Plateau regions was conducted in Huanxian City. Comparing the proposed urban ecological network of the Loess Plateau regions and the generated scheme with the overall planning scheme of 2016, the patch density and the largest patch index decreased by 1.522 and 13.794, respectively, while the fractal dimension, interspersion and juxtaposition index, the contagion index, and the connectivity index increased by 0.003, 2.188, 14.076, and 1.366, respectively. This trend proves that the research scheme improved in terms of ecological performance. Research conclusions can provide useful references for the construction of urban ecological networks in underdeveloped and ecologically vulnerable areas in China while offering guidelines for making decisions on the green development and management of urban spaces.