神木市生态安全格局构建与生态问题定量诊断

黄河流域生态保护和高质量发展是重大的国家战略，县域生态安全格局构建与生态问题定量诊断是实施生态保护修复的最基本单元。以神木市为研究对象，首先，基于电路理论构建神木市生态安全格局，将识别出的生态夹点、生态障碍点和低质量生态空间作为生态修复关键区域；其次，通过构建生态问题指标体系，在生态修复关键区域内定量化诊断现存生态问题；最后，通过生态问题指数(EPI)测算结果划定生态修复分区。研究表明：(1)神木市生态源地面积为411.64km²,以草地为主，主要分布在中部、东部和南部地区，源间生态廊道共63条，总长度约610.71km,中部地区的生态廊道较东南部密度大。(2)基于生态安全格局识别的生态修复关键区域包括生态夹点415个，面积达30.55km²;生态障碍点341个，面积共计25.72km²;低质量生态空间面积为1043.73km²。(3)生态修复关键区域内土壤侵蚀主要以微度侵蚀为主；地质灾害多发于采矿区以及黄土丘陵沟壑区；水源涵养低值区主要分布在低质量生态空间；林地和草地的退化程度呈现东部较中部和西南...

Construction of ecological security pattern and quantitative diagnosis of ecological problems in Shenmu City

Ecological protection and high-quality development in the Yellow River Basin are major national strategies. Construction of county-level ecological security pattern and the quantitative diagnosis of ecological problems are the basic units for implementing ecological protection and restoration. Taking Shenmu City as the research object, this paper firstly constructed the ecological security pattern of Shenmu City based on circuit theory, and took the identified ecological pinch points, ecological barrier points and low-quality ecological spaces as key areas for ecological restoration. Secondly, the existing ecological problems in the key areas of ecological restoration were quantitatively diagnosed. Finally, the key areas of ecological restoration zones were delineated through the calculation results of the ecological problem index (EPI). The result showed that:(1) the ecological sources'' area of Shenmu City was 411.64 km², mainly being grassland distributed in the central, eastern and southern regions. There were 63 ecological corridors between the ecological sources, with a total length of about 610.71 km, which were denser in the central region than those in the southeast. (2) The key areas of ecological restoration identification based on the ecological security pattern included 415 ecological pinch points with an area of 30.55 km², 341 ecological barrier points with an area of 25.72 km², and the area of low-quality ecological space with an area of 1043.73 km². (3) Soil erosion in the key areas of ecological restoration was mainly dominated by slight erosion. The geological disasters mostly occurred in mining areas and loess hilly and gully areas. Low-value areas of water conservation were mainly distributed in low-quality ecological spaces. The degradation degree of forests land and grassland was lower in the eastern than that in the middle and southwestern. The fragmentation degree of cultivated land was higher in the eastern and southeastern, but lower in the middle and southwestern. The areas with high desertification index were mainly distributed in the sandy land of low-quality ecological space. Some rivers, lakes, wetlands, and vegetation have been transformed to non-ecological land over time. (4) According to the EPI calculation results, the key areas of the ecological restoration could be further divided into ecological conservation areas, ecological improvement areas, key control areas and key restoration areas. In the future, the ecological restoration should be carried out according to the spatial distribution characteristics and land use status of each district. The research results provide a theoretical basis for the construction of ecological security patterns and quantitative diagnosis of ecological problems, and are of great significance for practicing the concept of green development and promoting ecological protection and high-quality development in the Yellow River Basin.