Consolidation area delimitation for supplemental prime farmland based on GIS and combined quality assessment model

The Consolidation Area for Supplemental Prime Farmland (CASPF) is a new concept in the current round of revising general land use planning, which is the concentrated cultivated land area where ordinary farmland can be adjusted to and can supplement basic farmland during the implementation of land use planning. Delimitation of the CASPF is very important for achieving the goal of protecting prime farmland. According to the features of CASPF, this paper established a comprehensive evaluation indicator system for choosing ordinary farmland as CASPF, which consists of 16 indicators. Considering the multiple requirements of quality, quantity and space distribution for basic farmland delimitation as CASPF, there are two steps in the ordinary farmland screening procedure, namely sorting and selecting the farmland plots by their quality order and locating the selected plots. In this study, according to the characteristics of these two steps, GIS technology was used to extract the quality data of farmland plots, and Fuzzy Optimization Model and Hierarchical Attribute Model were used in the screening of candidate plots for prime farmland. The average values of plots evaluation results calculated with the two models were taken as the basis for quality ordering. Finally, taking Meijiang town, Xiushan county, Chongqing city as examples, the specific locations of CASPF were determined with the help of GIS spatial analysis function. This combined assessment model can avoid the limitations of single evaluation method and obtain more scientific results.