The Warning Assessment Of Ecological Security Subsequent Development Of The Three Gorges Reservoir Based On System Dynamics

Ecological security is an interdisciplinary of natural science and social science. There is still not an internationally accepted definition of ecological security at present. In this paper, ecological security model of Three Gorges Reservoir in Chongqing was established using system dynamics.Firstly, according to ecological security analysis of the status quo of the Three Gorges Reservoir area, the determined ecological security stress factors are contained natural, social and economic.Secondly, according to special geographical features of Three Gorges reservoir, an improved DPSIR model, which involves all aspects of society, economy and environment, was applied to establish an evaluation index system of ecological security. AHP method with objective and subjective combination characteristics was selected to endow these indices weight.Thirdly, based on the ecosystem characteristics of Three Gorges reservoir, a system dynamics model containing economy, population, and environmental subsystems was developed. The model was set up using specialized software Vensim PLE. The comparison of results from calibration and observation shows that the model corresponds to observed behaviors, and the simulated values fit well with the observed data and changing trends. Moreover, 3 scenarios named sustainable development, resource exhaustion, and natural state were designed to simulate future change of ecological security.Fourthly according to the requirements of multi-level, multi-dimensional and dynamic in ecological security warning, the paper selected as the Three Gorges Reservoir study area, established eco-security warning indicator system including the dynamic monitoring subsystem, the security assessment subsystem, the alarm forecasting subsystem and the decision management subsystem. Then we used the variable weight and matter element analysis model to estimate the early-warning level of ecological security of the Three Gorges Reservoir.