[Ecological Vulnerability Evaluation and Its Driving Mechanism of Mineral Resource-based Region]

Dingxi has abundant mineral resources and complex landforms， and the contradiction between ecological environment and economic development is prominent. Thus， studying the ecological vulnerability and driving mechanism of Dingxi City has great significance for the protection and management of the regional ecological environment and the classification and evaluation methods of mine restoration. Based on a combination of four screening methods and four machine learning prediction models， 19 basic environmental factors were selected from natural and social environmental factors， and the spatial distribution characteristics of ecological vulnerability in Dingxi City were compared and analyzed by using training and testing prediction models. Based on the principle of screening method， correlation， principal component analysis， regression analysis， and importance analysis of the selected basic environmental factors were carried out to reveal the driving mechanism. The results follow： ① The prediction accuracy of the prediction model based on the screening method was entirely above 80%， which meets the accuracy requirements of ecological vulnerability assessment. Therefore， the combined model can be used as a new method for mine ecological environment assessment and ecological vulnerability assessment. ② The ecologically fragile area of Dingxi City showed a spatial distribution pattern of "high in the northeast， low in the middle， and high in the southwest." The ecological environment in the central， western， and southeastern regions is better than the environment in the northeast and southwest regions. ③ The annual average precipitation， road density， and river network density in the study area， which are the results of the combined effects of climate， human activities， and complex topography， are the main driving factors of ecological vulnerability. ④ The historical mining area is indeed a serious ecologically fragile area， and other types of mining areas are also closely related to the ecological vulnerability in the region. Therefore， the timely treatment and restoration of mining areas is a key link in the protection of the ecological environment.