RESUMEN
Due to rapid population growth, industrialization, and urbanization, it is particularly important to address the increasingly serious ecological security issues in the process of urbanization, while it is important to grasp the impact of changes in land use structure on ecological security for scientific planning and to aid decision-making. As a typical valley basin industrialized city in northwest China, Lanzhou has complex geomorphology and climate with distinct regional characteristics, and the relationship between land use and ecological security is complex. In order to understand the current status and influencing factors of ecological security in various regions of Lanzhou, and to explore the intrinsic connection between ecological security and land use, this study constructed an ecological security evaluation index system based on the pressure-state-response (PSR) model with 14 secondary factors including natural, social, and economic factors. Based on the entropy method, GIS was used to analyze the trend of ecological security in each district and to clarify the coupling relationship between ecological security and land use change in Lanzhou City. The results show that the ecological security index (ESI) of Xigu District, a typical heavy industrial area, increased from 0.26 to 0.35, and the ESI of Yuzhong County, an agricultural development area, increased from 0.51 to 0.55 from 2000 to 2017. Low ESI was mainly distributed in areas with developed heavy industry, while high ESI was mainly found in areas with favorable natural conditions and mainly agricultural development. Economic factors were the leading factors affecting the ecological security of Lanzhou. In general, changes in land use structure and ecological security were inextricably linked, and the two influence and interact with each other. These results could provide some reference for the study of ecological security development and land use change in typical river valley cities and also provide a new path for other cities to study ecological security and the conservation of the ecological environment.
