【摘要】 耕地保护是基于耕地功能需求的保护,生产功能、生态服务功能和景观文化功能等需求是巨型城市区基本的耕地功能需求,其耕地保护阈值应考虑这种耕地多功能需求的区域特殊性。论文以耕地多功能管理为基本理论依据,以现有耕地保护阈值研究为基础,结合生态绿当量、碳氧平衡法和景观格局分析等最小生态用地需求量测算理论和方法,构建了集粮食生产功能和生态服务功能需求于一体的巨型城市区耕地保护阈值测算模型。模型侧重于潜在粮食生产能力的保护和现实生态用地结构的优化,将保护阈值区分为实有耕地保护阈值和其他可耕地保护阈值两部分。到2030年末珠江三角洲耕地保护总阈值为104.17×104hm2,其中实有耕地保护阈值48.16×104hm2,其他可耕地保护阈值56.01×104hm2,模型具有一定的可行性。更多还原

【Abstract】 Cultivated land is the primary resource for the sustainable development of agriculture, society and economy, and its protection has become one of the core objectives of land policy-making in China. Food production, ecological service and sightseeing are the basic functional demands in mega-urban regions, forming the regional particularity which should be fully analyzed in the threshold calculation of cultivated land protection. In a given time period, the demand degree for a certain function in a region depends on the supply sources of the function and its alternatives, and the factual function may not be consistent with the demands as a result of function’s imports from other regions. The total demand for grain has increased dramatically in mega-urban regions since more and more people have settled there. While sufficient food supply from domestic and international grain market has secured the great consumption, the factual grain production function of cultivated land has become weaker and weaker, but the potential grain production capacity of arable land should be a primary objective so as to face the unexpected challenge of food shortage. It is arable land, not only cultivated land, should be protected from this perspective. The demand for social security function of cultivated land is decreasing because more efficient rural social security system has been established in mega-urban regions. Demands for ecological functions, such as soil conservation, hydrologic modulation,air cleaning, and insulating construction land, have increased greatly as a result of serious ecological and environmental problems, while it cannot be imported from outer regions just as the grain consumption does, and also it cannot be supplied by"travel"just as sightseeing function does, it must depend on the region itself. So the ecological function should be an important concern in the calculation of cultivated land protection threshold. Furthermore, cultivated land should be planned systematically within the whole ecological land system. Based on above analysis, the minimum threshold model of arable land protection for food security(SF), the minimum threshold model of tillage land protection for eco- security(SE) and the total threshold model are developed on the base of minimum area per capita model and urban minimum ecological land use planning, such as ecological green equivalent, carbon-oxygen balance and landscape security pattern. The total threshold(SA) is divided into tillage land(SC) and other arable land(SO), laying emphasis on potential productivity protection and structural optimization of ecological land. SCis equal to the minimum value between SEand SB(the actual cultivated land of base year); if SFis greater than SC, SOis the difference between SFand SC; if SFis no larger than SC, SOis equal to 0. The total threshold(SA) at the end of year 2030 is 104.17×104hm2, with the tillage land(SC) 48.16×104hm2and other arable land(SO) 56.01×104hm2. This case study indicates, to some extent, above calculation models are feasible and suitable.更多还原