Improved Mothed And Its Application For Water Quality Assessment And Water Environmental Carrying Capacity Calculation

To evaluate the water quality and calculation,the water environmental carrying capacity are the basic tasks for water enviromental planing and management. Based on the characteristics of random,fuzziness, and uncertainty of water environmental system, uncertained mathematic theories are used to improve the traditional water environmental models.For water quality assessment , by way of the existing model and denoting the monitoring data of water quality for each index as blind numbers, a new water quality index model with blind number parameters and a blind reliability model for identifying the ranks of water quality are established primarily. According to these two models, not only the possible interval values and their corresponding faith degrees for aggregative index number of water quality, but also the ranks of water quality of evaluated waters can be identified. Study results show that it is feasible and reliable employ the blind number theory for water quality assessment.By way of the existing fuzzy linear regression model, a new linear regression model with triangular fuzzy parameters is established for river water quality forecast. According to the upward model, the trend of river water quality can be reflected by means of triangular fuzzy numbers. Using theα-cut technique for fuzzy numbers, the forecast values of river water quality can' be converted from triangular fuzzy numbers into interval values corresponding to the given confidence levelα. Study results show that the fuzzy linear regression model with triangular fuzzy parameters is suitable for river water quality forecast.For water environmental carrying capacity,the blind number theory and triangular fuzzy number theory are used to improve the water environmental carrying capacity model respectively .On the basis, two new modles with blind number parameters and triangular fuzzy parameters are established respectively. It is proved reasonable in calculating the environmental capacity of river and reservoir.In the end, the blind number theory and triangular fuzzy number theory are used to improve the water quality assessment, the river water quality forecast and the water environmental carrying capacity. Except for water,it can be used widely in air,soil,sea,travle and population.