Abstract: Taking Kang County, Longnan City, Gansu Province as an example, based on land use data from 1985 to 2020, the spatial and temporal change characteristics of cultivated land resources in Kang County were analyzed by using land use transfer matrix, dynamic attitude of cultivated land use and nuclear density analysis, and zoning optimization analysis of cultivated land resources in Kang County was carried out by introducing poly-tillage ratio index and sloping land characteristic index. The results showed that, in general, the cultivated land area and the average slope of Kang County were decreasing year by year, the cultivated land was mainly transferred into forest land, and the land use types converted to cultivated land were mainly construction land and forest land. The total amount of cultivated land resources in the study area with slopes equal to or higher than 15° had decreased the most, the amount of cultivated land decreased significantly between 1995 and 2000, and the overall amount of cultivated land did not change much between 2000 and 2020. The areas with the highest frequency and magnitude of decrease in cultivated land resources were mainly located in the northeastern and central of the study area; the areas with the highest frequency and magnitude of increase in cultivated land resources were mainly located in the southeastern and southwestern of the study area. The areas with a shortage of cultivated land resources were mainly distributed in the north and south of the study area, and the areas with high difficulty in cultivation were mainly distributed in the north and southeast of the study area. Among the coupled cultivated land resource optimization types, the cultivated land restriction area was the most, and the industrial transformation area was the least.

Key words: land use, spatio-temporal evolution, cultivated land resource optimization, Kang County