Water Environment Pollution Assessment Based On The Stochastic Simulation-triangular Fuzzy Numbers And The Extended Blind Number Model

Water resources are the indispensable material basis for human survival and development. With the continuous development of China's economy and society, the problem of water pollution is increasing. What's more, the river heavy metal pollution and lake eutrophication phenomenon is prominent. Evaluation of water environment as a basic work, have become the prerequisite and basis for the prevention and control of water pollution. It has great significance for the protection of water resources and water environment improvement. At present, the river sediment heavy metal pollution and lake eutrophication assessment method has been more, but most for deterministic or system in one aspect of the uncertainty evaluation. Because of the uncertainty of various objective and subjective cognition, water environment is a complex system which random, fuzzy, grey and unascertained and other uncertainties coexist or, cross-existence. Furthermore, the source, nature and type of these uncertain information are complex. If in the course of evaluation, ignoring the information is more likely to produce the wrong result and lead to mistakes in decision making.In this paper, stochastic simulation model and blind number were connected with triangular fuzzy number respectively, based on the water environment system in the presence of random, fuzzy, grey and unascertained. Then, stochastic simulation and triangular fuzzy numbers model(SS-TFN) and extended blind numbers model were built. These models were applied in the evaluation of risk of heavy metal pollution in Xiangjiang and eutrophication of Dongting Lake. The uncertainty factors were analyzed, and more objective, true ground water pollution of the environment were represented in order to reduce the uncertainties in the process of assessment. They could provide more comprehensive information for its prevention and treatment, which supplied a new method for evaluation of water environment.The evaluation of the pollution of heavy metals in sediments of river based on stochastic simulation and triangular fuzzy numbers model and the eutrophication assessment of lake trophic state based on extended blind numbers model were compared with the conventional deterministic method. The results showed that these two kinds of model could get the interval and its corresponding membership degree of heavy metals pollution index and comprehensive nutrition index corresponding to the value simply and fast, so as to obtain the comprehensive pollution level, and could determine the area which had deteriorated.To a certain extent, these models could reduce the uncertainties in the assessment process, which can provide decision makers with more reliable data, and has better practicability and maneuverability. The water pollution situation could be reflected more comprehensive and true. Besides, the relevant region of pollution would be regarded as the focus of supervision and control object, and effective method of prevention and treatment could be carried out.