Functional zoning of the cultivated land around the city under multi-scenario simulation

Food security is critical to the overall economic and social development in China. Accurate delineation of functional zoning is one of the most important means to balance cultivated land protection and economic development in food security. Fine management of cultivated land resources can be expected to realize in modern agriculture. Taking the main urban area of Changzhou City as an example, this study aims to simulate and then predict the land use under natural development, cultivated land protection, and sustainable development in 2030. Patch-generating land use simulation (PLUS) model was also used, according to the direction of future urban development. The hot spot analysis was then used to identify the cold and hot spot areas in the future cultivated land under the three scenarios from 2020 to 2030. Meanwhile, a comprehensive suitability evaluation system was constructed for the cultivated land from three aspects: production suitability, spatial cluster, and location convenience. A weighted superposition was conducted to evaluate the comprehensive suitability of cultivated land. The scores of individual indexes in each evaluation unit were calculated to combine the comprehensive weights of indexes for the scores of each dimension. The k-means clustering with the contour coefficient in Python was also selected to evaluate the partition, according to the scale of the administrative village. Moreover, the hot spot analysis and spatial clustering were combined to balance the functional zoning of cultivated land under the scenario of sustainable development. The results showed as follows. 1) The spatial distribution of land use types overlapped under different scenarios. The hot spots of cultivated land in the future were mainly distributed around the central urban area, where the trend was more in the east and south and less in the west and north. The cold spots were mainly distributed in the north of Xinbei District, the southwest of Zhonglou District, as well as the east and west of Wujin District. The local cluster of cultivated land change significance was ranked in the descending order of the natural development, sustainable development, cultivated land protection scenario. 2) The comprehensive evaluation was realized on the production suitability, spatial cluster, and location convenience. The study area was preliminarily divided into type Ⅰ, Ⅱ, Ⅲ, and Ⅳ regions, according to the clustering, where the proportions of the cultivated land area were 38.71%, 32.73%, 19.80%, and 8.76%, respectively. 3) Four types of study areas were also divided into the major grain-producing, urban agricultural, farmland improvement, and urban-rural transition areas. The zoning type indicated the productivity, location conditions, agglomeration characteristics, and stability of cultivated land. In conclusion, the finding can be beneficial to implement the regulatory measures for the different types of cultivated land around big cities, further improving the scientific allocation and full utilization of limited land resources. An important link can be strengthened to balance food security and economic development. The findings can provide a strong reference for the zoning, utilization, and protection of cultivated land around similar cities in China.