JOURNAL OF NATURAL RESOURCES ›› 2015, Vol. 30 ›› Issue (8): 1255-1266.doi: 10.11849/zrzyxb.2015.08.002

• Resource Utilization and Management • Previous Articles     Next Articles

Cultivated Land Protection Threshold Calculation from Perspective of Multifunctional Demands for Cultivated Land in Mega-urban Region—A Case Study in the Pearl River Delta

DU Ji-feng, YUAN Zhong-you   

  1. College of Public Management, South China Agricultural University, Guangzhou 510642, China
  • Received:2014-05-12 Online:2015-08-15 Published:2015-08-15

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. SC is equal to the minimum value between SE and SB (the actual cultivated land of base year); if SF is greater than SC, SO is the difference between SF and SC; if SF is no larger than SC, SO is equal to 0. The total threshold (SA) at the end of year 2030 is 104.17×104 hm2, with the tillage land (SC) 48.16×104 hm2 and other arable land (SO) 56.01×104 hm2. This case study indicates, to some extent, above calculation models are feasible and suitable.

CLC Number: 

  • F301.21