Abstract: Landscape ecological risk assessment is a comprehensive means for the spatial optimization allocation of land resources and the decision-making design of ecological resources management, which can provide a new idea for quantitative assessment of regional ecological security. We analyzed the characteristics of the temporal and spatial variations of land use in Xining City from 1980 to 2020, and explored the characteristics of the temporal and spatial variations of landscape ecological risks. The results showed that: (1) Grassland accounted for more than 51% of the total area of Xining City, mainly with medium/low coverage grassland. From 1980 to 2020, the area of cultivated land decreased by 97.42 km², while the construction land increased by 103.89 km². (2) The land use structure was relatively stable before 2000, and the degree of land use change was active after 2000. During the four decades, the area of transferred from cultivated land was the largest at 109.69 km², while the area transferred into construction land was the largest at 104.44 km². (3) The landscape ecological risk index of Xining City was 0.288, and the landscape ecological security status was generally stable. The ecological risk levels were mainly at low and the relatively low ecological risks, accounting for more than 70% of Xining’s area. (4) The global Moran’s I values of Xining’s landscape ecological risk in the five periods were 0.712, 0.720, 0.724, 0.741, 0.764 respectively, with a spatial distribution pattern being dominated by low-low and high-high clusters. The degree of spatial autocorrelation increased gradually, and the trend of spatial convergence strengthened continuously. The paths of optimal allocation of land resources include: scientifically estimating the scale threshold of production, living, and ecological lands in the land use structure, avoiding excessive development and utilization of production and living land and occupying ecological space, improving the quality of grassland and arable land resources, and strengthening the overflow benefits of ecological functions and values of woodland resources, rational planning of the scale and intensity of construction land development, cultivating landscape ecological corridors of waters and construction land, and moderately increasing the area of ecological land in the urban area. Such suggestions may ensure the continued improvement of ecological security pattern in Xining City.

Key words: land use change, ecological risk index, landscape pattern, spatial autocorrelation, Xining City.