Research On The Application Of Knowledge System Based On Rules For Water Quality Evaluation

With the rapid development of economic in China, town construction and industrial production expand continually. Nowadays, much water is polluted by industrial sewage and domestic sewage, so water pollution becomes one of the most serious environmental problems. Water quality monitoring and evaluation is considered as a main measure to manage water resource and control water pollution and it is more pop than before.Expert system is an intelligent computer program. It uses knowledge and inference to solve complex problems which can only be solved by experts. At present, although the application of expert system for water quality evaluation is less than others, the successful experience from some special application domain can be used for water quality evaluation. We can utilize the expert system to analyze and dispose water quality data, and then master water quality status and its trend of development. Finally, according to the result of water quality evaluation, we can provide better academic references for water resource management and water environment protection.On the basis of the introduction of some common methods for water quality evaluation, we firstly analyze and compare these methods and obtain some conclusions. Then, we design knowledge base and inference rules by using the conclusions and consider them as the references to choose a method for water quality evaluation. Finally, we adopt Delphi as the main tool to develop the knowledge base, inference engine and user interface of the expert system based on rules for water quality evaluation. The aim is to simulate real experts to make decisions for water quality evaluation. According to the characteristics of water quality monitoring data, the expert system will choose the best method to calculate and analyze those monitoring data, and give reasonable evaluation result.The main research work in the paper is as follows:(1) We analyze the design idea of the expert system based on rules for water quality evaluation. And then we adopt three modules such as method-choose module, calculate-analyze module and result-evaluate module to construct the structure of the system.(2) On the basis of analyzing and comparing some common methods for water quality evaluation, we design and develop the knowledge base, inference engine and the way to acquire and maintain expert knowledge for the expert system. In addition, we develop the calculating and analyzing software on data fusion based on D-S evidence theory.(3) Considering water quality monitoring data from Yangtze River Port Water Environment Monitoring Center as the research object, we utilize the system to make some experiments. Finally, we validate the validity and feasibility of the expert system for water quality evaluation.