The Research Of System Dynamics On Reverting Agricultural Land To Forest Of Shan-bei Region

In history, the North Shaanxi was famous for its rich natural resources, forests and grass, and had abundant plants, but now, this region has become one of the most serious regions in the middle and up reaches of Yellow River for its soil erosion. Every year, over half of the billion-bedload influx to Yellow River from Yellow soil tableland comes from North Shaanxi. The fragile ecological environment brings on the people's poorly living and the low development economy. The first step to change the economic condition is to improve the fragile ecological environment. And it is pressing to father and ameliorate the ecological environment in North Shaanxi through conversion of cropland to forest.This thesis will roundly analyze all the factors, which are involved in reverting agricultural to forest, and the mechanism of reciprocity among these factors from the aspects of the ecological, economy and society based on systemic and unitary, by utilizing the system dynamics to analysis the system of Shan-bei reverting agricultural to forest.This paper begins from the form of the Shan-bei's fragile ecological environment, and analysis the general influence on ecological system, economy system and society system by actualizing the work of reverting agricultural to forest in North Shaanxi, and also, this paper analysis the function of the subsystem during the action. Finally, this thesis put forward the system dynamics of the reverting agricultural to forest in Shan-bei, and predicting the trends of every variable in system when the relevant parameter is changing through computer simulation. The result not only can offer scientific basis for Shan-bei government when they make layout and policy for natural environment preserving and fathering and economy development in reverting agricultural region, but also can offer data in economy guide line predicting for government. And at the same time, the result can help the government and the peasant conquer the anomaly on quantity and quality, and it can afford a reasonable guidance in creasing the peasants' income and keeping the reduced cultivated land.This paper is innovative application of system dynamics in the reverting agricultural land to forest. It puts forward a kind of comparative feasible theory solution for practical problem of the complicated social economy system through the simulation of system dynamics model, so at last, the result will offer a kind of methods to settle the problem of reverting agricultural to forest in Shan-bei region.