Research On Key Technology Of The Decision And Support System In Environmental Protection

With the development of Geographic Information System, Computer Science and Technology, Intelligent Control Technology and the popular of Management Information System in environmental system, the study of Environmental Decision and Support System (EDSS) is becoming the key and hot research field. EDSS can provide the deciders in environmental system with more useful and instant support information in the process of making decisions, and make it possible to make more effective and scientific decisions and modernization and standardization of the management of environmental protection system. At the same time, it can help develop the role of the exports in making decisions and dealing with the environmental accidents more instant and effective.EDSS is a sophistical large system including environmental planning subsystem, environmental evaluation subsystem, environment pollution emergency subsystem, environment alarm subsystem and ecological environment subsystem, which is involved in many scientific subjects. So the main task of the dissertation is to study the basic theory and application method in EDSS and the key technology in related subsystems including the study of the frame architecture of EDSS, location selection of the polluting factory, expert group decision system based on modified D_S evidence theory applied in environmental evaluation, the optimization route in emergency subsystem and their applications in emulation system whose aims are to testify all developed methods in dissertation. The study of the dissertation can help obtain more effective decision results, contribute to the popular of EDSS and provide better services to environmental management. The main contributions can be summarized in the following five parts.1. After analyzing the data flow, the business operation flow and the characteristics of the environmental system, the technique demands and functions are summed up in this dissertation. Then an application frame is presented and the platform of EDSS is designed. 2. In order to overcome deficiencies such as difficult to deal with conflict evidence and the large time cost in combing the evidences, a modified evidence combination rule is developed through rating the evidences according to their belief functions. Meantime, two different rating ways to rate the evidences are also presented based on the fuzzy sets or linearization the evidences' distances. Meanwhile, a quick calculation method is developed and testified. The typical and real instance shows this combination rule can combine highly conflicting evidences more quick and satisfactory. Moreover, in designing the environmental evaluation subsystem based on expert group decision system, a new model including two-layers evidence combination processes is developed, and the application of it in a water evaluation system testifies the feasibility and validity of our developed method.3. In establishing the location selection mathematical model in spatial decision support system, the conventional methods have deficiencies such as large time cost in searching process and difficult to locate the exact position because of less considering the images information. To improve the mathematical model, based on the remote image processing and modified particle swarm optimizer, a new method is introduced to the research of spatial decision support system for location selection of factory. As a remarkable improvement on the conventional methods, the mathematical model can be easily established by fully utilizing spatial information and attribute information in GIS.4. In studying the algorithms to select the optimization path in emergency subsystem, a modified optimization path finding algorithm with higher speed and better results than old ones is presented. In which, by the use of the hierarchical spatial modeling method, the optimization hierarchical traffic network is firstly set up. Then the start part and the end part of the optimization path are found through querying the pre-stored databases. At the same time, by applying a modified heuristic A* shortest path search algorithm which considering the traffic states of the road in searching path at the dynamic traffic environment, the main part of the optimization path is also obtained. And the real application in real-time traffic system shows the effective of our developed method. Finally, based on the study of the shortest path algorithms when the destination is changing, a modified shortest path algorithm with high speed and good results is presented. And the simulation using data from the real traffic system shows the developed method can get good balance between the time cost and the exact results.5. The emulation system of EDSS is designed, in which all new developed methods are applied using software program and testified. The results show that the developed methods can be used in the future real EDSS system.In the last chapter, after summarizing the contents of this dissertation, the further research issues are presented in detail, which will guide the future research direction in this field. Finally, the future applications of algorithms are also discussed in this dissertation.