Study On The Method Of Strategic Environmental Assessment On Water Planning Based On System Dynamic Model

Strategic Environmental Assessment (SEA) is the application of the Environmental Impact Assessment's principles and methods at the strategic level. It's the formal, systematic and comprehensive evaluation process to a policy, a plan or a program, including complete the SEA report and use the conclusions for decision-making. The purpose carrying out SEA is to eliminate or reduce the adverse impact because of the strategic defect in the future, and control the environmental problems such as environmental pollution and ecological degradation from the source.With the propose of the Sustainable Development, SEA is paid more and more attention, and become the importance and focus in the field of Environmental Impact Assessment. Since the concept of SEA was put forward, many studies about the SEA's theoretical system and methodology system have carried out, many developed countries and some developing countries have established their SEA system in some field. SEA in China has also made progress on the theoretical and practical research for nearly 20 years'development. However, there is still no more perfect and maturity of methodology for SEA, and most of the methods are still the EIA traditional methods, which has brought some constraints for SEA. Therefore, carrying out the study on SEA methodology has some theoretical and practical significance.System Dynamics (SD) is good at solving nonlinear, multivariable, high times, complex time-varying system, which can be used in SEA. Building a computer simulation model to predict the affection of a strategy from a macro-dynamic point, so as to provide guidance to decision-making.SD is used as the basic approach in this paper, and the"Water City, Lake Town"water planning in Hengshui, Hebei province as the case. And this paper approach to the application of SD model in the SEA, dividing the system into for subsystems which are population, economic, water resource and water environment. The system dynamic simulation model was constructed using the software Vensim-PLE, and analyzed the change of the system under different projects by changing the value of parameters.