System Dynamics Study On Eco-security Capacity In Yunyang County, Chongqing

In recent years, the ecological problems are becoming more and more serious due to people's destroy, which have given directly threat on the existence of human being and the national development. So the ecological problems are evolving eco-security one, which also become the focus between global academy and government of all the countries.Eco-security Carrying Capacity (ECC) is a kind of new method that evaluates eco- security, which had been put forward by a Chinese Scholar, Jingping Yang. Based on the applied production of Carrying Capacity in environmental science, this paper redefines Eco-security Carrying Capacity. At the same time, using the method of System Dynamics (SD) and taking Yunyang County as an example, the paper makes a trial of research on Eco-security Carrying Capacity of district.The article is divided into ten chapters. The whole structure as follows:The background, significance of Eco-security Carrying Capacity study and the work of this article are introduced in chapter 1.The theory of Eco-security Carrying Capacity is discussed in chapter 2. It consisted of two parts that are Eco-security and Eco-security Carrying Capacity. The origin, con- ception, characteristics, connotation, current situation and relations between two parts are separately introduced.It is introduced the method of System Dynamics in chapter 3. An approach to the problems of System Dynamics is divided into five steps include identifying system, analysis configuration, establishing model, analysis model and evaluation model.In chapter 4, the system of Eco-security Carrying Capacity in Yunyang Countyis identified, which consisted of the physical subsystem that is composed of natural geography, natural resources, ecological environment, the social subsystem that includes the population conditions , science and technology, the economic subsystem which comprises national economy and agriculture, industry, business, etc.On the basis of analyzing the population, resources, environment and social economic conditions of Yunyang County, the construction of Eco-security Carrying Capacity System in Yunyang County is established, the System Dynamics Model and feedback loops are built in chapter 5.Based on the feedback mechanism of subsystem and the principle of catching the main problems, the flow chart of Eco-security Carrying Capacity System and the equations of System Dynamics for subsystem are set up in chapter 6.In chapter 7, using Vensim Software the system dynamics model will be circulated after the parameters of model is set up. Through verifying the construction, historical behaviors that if or not fit historical data and the analysis of sensitivity, the validity and practicability of model is estimated. Following, Eco-security Carrying Capacity in Yunyang is predicted by the model.The policy experiments of Eco-security Carrying Capacity Model are discussed by the policy synthesis indexes of four aspects in chapter 8.According to the policy experiments, in chapter 9, after adjusting the policy parameters, at the same time, taking purchase grain into account at suitable time, Eco-security Carrying Capacity Model in Yunyang is optimized.Finally, this article gives out the conclusions. It clearly indicates that this model can explain the interrelations of each factor of Eco-security Carrying Capacity System about Yunyang, so it can predict Eco-security Carrying Capacity, and the results can be applied as a scientific foundation and reference for governmental development and plan.