Temporal Models Of Arable Land Resource Sustained Use For Ensuring Food Security And Its Policy Response Simulation

The loess plateau semi-arid area where Zhonlianchuan valley is becomes the peculiar stretch poorest area of the world. This poverty is due to a long-term drought, serious water and soil loss, natural relief, zoology circumstance character and relevant low level of natural zoology system's productivity and low level of agro-economic-social development. Since 1980's, the popularization of rainwater harvesting agro-technology constructed with rainwater harvesting project which help of people with basic living problem in 1990's. Presently, farmer's living improve after the project sported by Li Kacheng foundation 2001-2005. For now, the sustainable problem, especially the problem of arable land resource sustainable use for ensure food security should put on agenda.This research makes a model base on a new conception—agro-ecology-economic system, for help to take decision to ensure food security during long time in this agro-ecology-economy system. To build and to test this model, I made investigations in the farms and we used the figures of the government of this country.To build a basic temporal model of arable land resource sustainable use to ensure food security, I consider that the average surplus area is null, the average area just the area needed to ensure food security, and that each part of agro-ecology-economic system doesn't change. I put economic index which is needed by socioeconomic development: the lowest food security, population and the rate of population growth, the productivity of soil, into simple mathematics-ecology model, which includes the Logistic group growth model. This model is:Where A is the land area, P is population at the beginning,ΔP is the rate of population growth, Ea is the parameter of the model,it is the area to ensure food security based on the lowest food security standard and the productivity of soil.As the model includes growth rate of group's invariable population growth type, I can put t to Logistic group growth model. The system's largest population endured model is:P_t=P (1+ΔP)~tIn fact, the lowest food security will change while system economic society develops, every part of agro-ecology-economic system is changing, it is a dynamic system. In this research, I made also the temporal model of arable land resource sustainable use in the open agro-ecology-economics system.What this reasearch done the First, to compare with different index of Ea for ensure that the index with the lowest food security which index of developing countries can suitable for the valley. Second, to test this model I apply it on the figures since 1965 to 2005 and it shows when the arable land was sustainability used. Third, I make a simulation to provide the figures about the policies of arable land resource use, population and agro-technology. This simulation shows how the policies of arable land use, population and agro-technology are effective at the same time to change the time of use. Last, I make a simulation about how the time will be change under the government aiming to especially get the eco-sociality. This simulation gives to the government the figures of the extension of the arable land area, or of decreasing of the rate of population growth, or of increasing the productivity of soil. The fallowing are the main conclusions:(1) The time of arable land resource sustainable use change with any factor of the agro-ecology-economic system. The temporal model of arable land resource sustainable use is dynamic model.(2) The time of arable land resource sustainable use is positive with the arable land area, productivity of soil, while it is objective with the population, the rate of population growth.(3) Indexes of estimate the sustainability of arable land resource use are both the time of arable land sustainable use and the largest population endured of the arable land resource.In a word, the temporal model was build base on the noew conception agro-ecology-economic. It solve the theory problem was poited by Foster what about the ecology-economics. It is also solve the problem about that there are nou commund background for research in ecology, mathmatics, ecoeconomics and human-socialogy. It is the frist temporal model in research about soil resource used. The temporal model can be a determination's tool for local government for arable land resource sustainable use and management, population and population management decision, also the temporal model can provide the modeling analysis method and the simulate figures for the local government to make sustainability decision.