| The agricultural land resource is the basement of the agricultural production and sustainable development of national economy, which has the profound effect on the entironment and social stability. Since Reform and Opening-up, with the swift process of the industrialization and urbanization in China, the demand of agricultural land increases progressively and plenty of which has been converted to construction land constantly.Whereafter,the urban build-up area sprawls evidently, and the entironment and grain safety are all confronted with tempestuous threat. Nay, in rural-urban area land requisition triggers more conflicts. Therefore, the rural-urban land conversion is focus by the whole nation. Upon that controlling the agricultural land conversion rationally is the absolutely necessary means to guarantee the grain safety and eco-security, maintenance the social stability, adjust macroeconomic, promote the sustainable urban-rural integrated development.Using the cybernetics, system theory and economic theory, the study firstly analyzed the domestic actuality of the rural-urban land conversion and its management and control system. Secondly, the economic value, ecosystem value and social value change after conversion had been discussed and then the reasonable management and control target. Subsequently simulating the conversion control process, this paper built up the management and control frame of rural-urban land conversion. And then the four parts of the management and control frame was lucubrated, which were the urban supply and demand control, the conversion benefit allocation control, the conversion institution control and conversion decision index control.The core aim of the rural-urban land conversion is that the total welfare of region should be raised after it happened. It could be considered that the total welfare was made up of all the economic value, ecosystem value and social value of the transferred agricultural land. If the total welfare would be increased after conversion, the parcel should be developed, or protected conversely. The concrete aim of land transformation accordingly divides into four parts: rational adjustment 1) on urban land supply and demand; 2) benefit distribution among the related involver; 3) controlling institution; 4) decision on conversion quantity, time and location.( i) urban land supply and demand control. Using the controlling model and conception model, the thesis concludes that government should select the appropriate level of the directly transferred land, storing land and redemptory land in the first. Then it should know that the key to land supply control is the rural-urban land conversion control which is tightly related with both current requisite and storing land, also with the previous and the future. According to the land demand control, governors should satisfy the consumptive land demand and strictly restrain the investment land demand by adjusting its land use charge, and try their best to save on urban construction land for decreasing the agricultural land conversion pressure.(ii) conversion benefits distribution control. Based on the game theory model, the study infers that the requisition price and transaction price should be logically determined by government. Restriction on these two kinds of price could coordinate the benefit between government and developers. With regard to the transaction price, it should not overstep the net benefit of the parcel, and it's minimal rested with the development benefit and cost, and illegal conversion fine. Conversion benefit allocation is a system project, so the land compensation price, requisition price, illegal conversion disposal and transaction cost should all be considered.(iii) controlling institution of agricultural land conversion. The controlling institution composes of two parts, the organization structure institution and other concrete control institution. Depending on the cybernetics, the author concludes that the close loop control of agricultural land conversion has more effect and less efficiency than the open loop on the local government disturbance. As the feedback control organization, the land supervision and inspection bureau should maintain the independence of superintendence, and pay more attention on the efficiency of higher land management organ.Considering the planning control and the land use control, the latter has nothing to do with the development value of collective land in the rural-urban fringe during the protection of regional eco-security and grain security, and may lead to the developer rent-seeking activities. Regarding the land development project, government should be supposed to process the relationship of construction examination and the agricultural land conversion emphatically, and unifies the information technology to strengthen its management.(iv) agricultural land conversion decision-making control. Considering the conversion decision-making, the thesis has analyzed the time, the spatial and quantity decision thoroughly, and conducts the empirical study on the Hongshan district in Wuhan.To the quantity decision-making, governors should in overall evaluate the grain and other food security demand, the urban development demand, the benefit change through in some time. To the time decision-making, a suboptimal decision-making is more feasible, and may reduce the erroneous decision risk. To the spatial decision-making, the information technology and econometric method is used to calculate the parcel conversion probability which was the basis of establishing a reasonable spatial control strategy. The research indicates that the key to control the land conversion is the calculation of conversion probability. After obtaining it the government can make the conversion control zoning plan based on the agricultural land use suitability. |
