Objective  The essence of “Trinity Protection” for cultivated land is the coordinated protection of the quantity, quality and ecology. Since cultivated land has differences in types and structures, analyzing of the regional differences in the quantity, quality and ecological spatial pattern of paddy field and dry land within cultivated land, and finding out the differences in the dominant factors affecting the spatial distribution of paddy field and dry land in different regions can provide a reference to the differentiated paths of the “Trinity Protection” for cultivated land.

  Method  Taking land use status data and cultivated land quality grade evaluation results in 2018 as the main data sources, this paper used topographic distribution index, landscape pattern index and geographic detector to study the quantity, quality, ecological characteristics and formation mechanism of paddy field and dry land in the eastern part (Wushan County as the example), middle part (Wanzhou District as the example), western part (Shapingba District as the example) of the Chongqing reservoir.

  Result  ① In Shapingba District, Wanzhou District, and Wushan County, the ratio of paddy field and dry land was 42:58, 51:49, and 9:91. The paddy field was mainly distributed in low elevated, gentle sloped, and low topographic distribution index areas. And the dry land was mainly distributed in high elevated, steep sloped, and high topographic distribution index areas. ② The quality of paddy field and dry land increased significantly from the first to the end of the reservoir, and the quality of upland land increased from Shapingba to Wushan. ③ The plaque densities of paddy field and dry land (28.53 and 24.46) in the Shapingba District were about 10 times higher than those of the other two districts, and the SHDI of paddy field and dry land (5.6 and 4.43) in Wushan County were about 10 times higher than those of the other two districts. ④ The paddy field and dry land in the reservoir areas were affected by many factors, among which rural employment personnel and slope factors are the main factors. After the geolocation probes interact, the slope and rural employment personnel on dry land were up to first and second place. The explanatory power of slope on paddy field was up to first place.

  Conclusion  In Wushan country and Wanzhou district, the core area of ecological conservation and development, the quantity of paddy field and dry land is large but the quality is low. In Shapingba district, the core area of urban function, the quantity of paddy field and dry land is less but the quality is high. The cultivated land in each region is greatly affected by topography. So, it should be carried out by means of local conditional different types when they protect and restore the cultivated land, so as to stabilize a certain quantity and quality of paddy field and dry land.