The Research On Decision Support System For Evaluation And Analysis Of The Water Environment Of The Dongting Lake

It is of importance for the scientific operating management of water environment, the decision support, and the sustainable development of the ecological environment to make quantitative evaluation and give the intelligent analysis for the pollution of the water environment and to find out its potential rule and knowledge. This essay chooses the water environment of 14 rivermonitoring sections as the research area and makes a study of the evaluation analysis and decision support system of the water environment of Dongting Lake under the guidance of thesoftware engineering principle and on the basis of the data Mining technology, theDecision Support System, the Thinkphp framework technology, the software designing pattern, and the database access technology. The results are as follows:1.On account of water environment of the researching areas in the Dongting lake and combining the features of the requirements analysis and the ones of theDecision Support System, this study designs thefunctionality on Front-End and Back-End for this system; based on the cooperation of multiple models, a model library is constructed to give a quantitative assessment to the state of nutrition of the water environment of the Dongting lake, the main pollutants of the monitored sections, and the comprehensive pollution index of the water quality; we also construct a knowledge base, obtain the knowledge association rules, the knowledge classification rules of the decision tree analysis, and the knowledge model of the functional cluster among the chose permanganate index, COD, BOD5, NH3-N, total phosphorus, arsenic, mercury, cadmium(sexavalence), oil, anionic surfaceactive agent, sulfide, coliform bacteria, etc, and find out the features of every pollution type and the relevant area.2. With the integration of using the Thinkphp frame technology, MVC designing model, and we realize the database visiting technology, the evaluation, analysis, and decision support system of the water environment of Dong ting lake based on V-structure, setting friendliness, the qualitative and quantitative evaluation analysis of human-computer interaction, data mining, aided prediction and decision-making, and visual output as a whole.3. The quantitative evaluation and the analysis and empirical research are given to the water environment of the Dongting lakes by applying this system. As the real evidence confirms, the state of nutrition of the Dongting lake over the past 10 years belongs to middle malnutrition; the main pollutants in the Dongting lake are total phosphorus(based on P), COD, coliform bacteria, permanganate index, NH3—N, five-day BOD. The rate of pollution shared is 16.9%,15.2%,14.2%,12.6%,9.7%, and 8.8%. In the meantime, the main pollution situation in every sections were gained; its comprehensive pollution index is among 0.2355 and 0.6428; the most polluted body is the east part, with the index,0.6428 and the least polluted one is the section in Xiao Hezu, with the index 0.2355. The average index of the whole lake is 0.3555. It also shows the capability, validity, and practicality of the decision support system. Also, it can assist the scientific management and decision support of the evaluation and analysis of the water environment.