Three-level concentrated prime farmland zoning and classified regulatory mechanism in suburb of metropolis

Abstract: In view of increasing acute contradiction between urban expansion and farmland preservation, landscape and ownership fragmentation and the unstable overall layout characteristics of prime farmland in the metropolitan suburb, it is of great significance to study three-level concentrated prime farmland protection areas zoning and classified regulatory mechanism in the metropolitan suburb, which would keep the balance between the farmland preservation and urban development, and promote intensive and innovative land use. The paper aimed at exploring the permanent protection mechanism of prime farmland in metropolitan suburb combining protection with development, management, and environment improvement. Taking the typical metropolis suburb Changping District as the case study area, this paper firstly specified five objectives of the permanent protection mechanism, namely, the layout centralization, construction reduction, function diversification, management differentiation and capital intensification. With the concentrated prime farmland identification index system built, composed of 11 indicators, this paper analyzed the concentrated degree, the stability and rehabilitation potential. Data mainly comes from the second national land survey data updated to 2013 and land use planning database of Changping District. Meanwhile, alternative concentrated prime farmland areas were filtered and classified, according to the AHP identification results and the classify guideline of "Function, Spatial, Scale" principle. Three levels were categorized, the municipal-level, the district-level and the township-level respectively. The three-level concentrated prime farmland special planning is used to clarify the protection responsibility target at all levels and spatial control regulation, determine the evaluation indexes such as quantity, quality and function of prime farmland, and establish the "economic compensation and index reward" joint horizontal mechanism and three-level "rewards and punishments" joint vertical mechanism.The results indicated that: 13 three-classified prime farmland protection areas were demarcated including one municipal concentrated protection area, six district areas and six township areas, which achieved 96.63% of the prime farmland protection in Changping District. Three-classified farmland protection areas zoning revitalized the stock of construction land effectively, taped the reserve cultivated land resources fully, and increased 1 149.97 hm2 cultivated land. The zoning also relieved the landscape and ownership fragmentation, enhanced the management unit scale to 38.76 hm2, and lowered the degree of landscape and ownership fragmentation to 1.21%. In addition, it optimized the farmland landscape pattern, expanded the multiple function of basic farmland utility: after delimiting 6 809.06 hm2 basic production function farmland protection area, it also expanded 1 172.88 hm2 landscape function centralized protection area, 1 003.03 hm2 ecological function protected area, and 807.03 hm2 blocking function centralized protection area. Moreover, it improved the prime farmland protection enthusiasm of the township and reduced the urban burden of two levels of capital and management pressure. The results could save 329.83 million Yuan for financial capital.The mechanism, three-level concentrated prime farmland protection areas zoning and classified regulatory in the metropolitan suburb, can guide the prime farmland concentrating, optimize the layout of prime farmland protection areas, extend the multi-function roles of prime farmland, strengthen the decentralized management of prime farmland, concentrate prime farmland capital allocation, then promote the scale management of prime farmland and improve the quality of the protection. With the farmland landscape pattern optimized and protection fund allocation efficiency and management efficiency improved, the results can help provide reference to decision makers and relevant researches for the national spatial planning of prime farmland protection and targeted policies making.