Multi-function evaluation and functional zoning of suburban cultivated land using MCR-InVEST model

Abstract: Suburban areas can be the urban-rural integration areas, totally different from the urban built-up and traditional rural areas. It is of great significance to reveal the multi-functional spatial differentiation characteristics of cultivated land resources in suburban areas, in order to promote the conservation and development of cultivated land. Taking the suburban areas of Nanchang City as the study area, this study aims to implement the multi-function evaluation and functional zoning of suburban cultivated land using the MCR-InVEST model. The field soil sampling was first conducted using the cultivated land map spots and townships in the Third National Land Survey as the basic research units. The multifunctionality of cultivated land was then quantified using the multi-source data, the integrated index, and the MCR-InVEST model. The multifunctional zoning of cultivated land was also carried out after evaluation. The spatial variation of multifunctional cultivated land in the suburban areas was revealed to identify the multifunctional characteristics of regional cultivated land. The results showed that: (1) there was a high production function level of cultivated land in the suburban areas, with an area of 16 358.31 hm2 of the medium to high grade (accounting for 78% of the total), which were mainly located in the East Lake District, Qingshan Lake District, and Wanli Administration. The high cultural landscape function level was also found with an area of 15 295.73 hm2 of the medium to high grade (accounting for 73%). The high-grade areas were located in the East Lake District and Maqiu Town in High-tech District. There was the medium ecological function level of the most cultivated land, with an area of 11 010.19 hm2 (accounting for 52%), where the high-grade areas were mainly located in the Wanli Administration. The areas of multi-functional high, medium, and low-grade spots were 3755.26 (accounting for 18%), 7453.83 (accounting for 35%), and 9818.65 (accounting for 47%) hm2, respectively, in the comprehensive view of the multi-functional index of cultivated land. Spatially, the high-grade areas were mainly located in the East Lake District, Economic Development Zone, Central Qingshan Lake District, North Central Wanli Administration, and Southeast Honggu Tan District; the medium-grade areas were mainly located in the Honggu Tan District, West High-tech District, East Lake District, and North Economic Development Zone; the low-grade areas were mainly located in the East High-tech District, North Honggu Tan District, and Northeast Economic Development Zone. Furthermore, there was geographical convergence in the high, medium, and low-grade areas of the multifunctional integrated score in the cultivated land. (2) Six functional primary and eleven secondary zoning areas were identified, according to the theoretical framework of multifunctional zoning of cultivated land and the multifunctional cultivated land in townships. The multi-functions of cultivated land were greatly varied in the different areas of suburban areas. Differentiated strategies can be expected to serve as the development and protection of cultivated land, according to the functional characteristics of regional cultivated land. The finding can provide a scientific basis to optimize the spatial pattern of cultivated land in suburban areas, thus promoting the integrated development of cultivated land.