CA simulation and verification of cultivated land planning based on land suitability

Abstract: CA simulation system of cultivated land planning can be used for planning cultivated land scientifically and rationally, so as to provide a reference for managers to make the general land use planning. Indices constraining and partitions controlling, as the existing pattern of general land use planning, is to ensure the total amount stable of cultivated land. However, phenomenon such as the unreasonable index of land quantity, the inadequate index of building land occupation, and the decline of cultivated land quality from 'Dynamic Balance of Total Amount of Cultivated Land', leads to the relevant departments cannot but make adjustments to the planning. Previous research of cultivated land is mainly focused on its protection, evaluation as well as change. There is a little literature on cultivated land planning. CA simulation system is a user-defined tool of ArcGIS, which is easy to be invoked in Geographic Information System (GIS). In the CA simulation system, the land suitability and planning indicators are taken as the cell transformation rule and constraint condition respectively, and optimal probability is used to select strategy. The paper taking Lankao County in Henan Province as example, selected the natural factors which affect the distribution of cultivated land, including soil texture, soil organic matter, effective thickness of soil layer, irrigation guarantee rate, distance to roads, distance to villages and slope; the ecological limiting factors of river and forest land that restrict the spatial distribution of cultivated land; and competitive factors for the conversion of other land to cultivated land from the three aspects of suitability, limitation and competition. Delphi method and expert scoring method were applied to calculating the weights of those factors. The evaluation score of cultivated land suitability is 0.46-0.91, while that of land suitability is 0.49-0.90 combining with spatial neighborhood analysis. The research result shows that in 2020 the area of cultivated land in Lankao County will increase by 8 000.69 hm2 and reach to 76 411.32 hm2 by overlaying with the land use status map in 2009. Because the urban development made the area of cultivated land decreased by 226.44 hm2, while the utilization conversion of village, inland beach, orchard land and other land made the area of cultivated land increased by 8 227.13 hm2. The results show that the quality of cultivated land in 2020 is relatively higher than that of the cultivated land in current land use planning, and the space distribution is stable by avoiding the town development, ecological protection and other factors. The study has important guiding significance for the future land planning.