Study On Cell Mapping Algorithm To Simulate Eutrophication Polluting Behavior In Three-Gorges Valley

Environmental prediction is a theoretical base of environmental programming, pollution prevention and environmental adjustment and control. The environmental contaminative prediction research on valley eutrophication is one of the most important aspects in water environmental protection. As we know that even under the current hydrological conditions, TP and TN contamination along Yangtze River valley, especially along the main sub-rivers such as Wujiang river valley, would be higher than the standard level of national water quality. The velocity of flow will become slower dramatically when Three-Gorges reservoir has been constructed so that the eutrophication would take place in the whole reservoir area, and an important task to resolve on water environmental protection in Three-Gorges reservoir will be necessary. The causes and some other key factors of the valley eutrophication are analyzed in this paper. Besides, the possibilities were discussed on the occurrence of valley eutrophication before and after completing Three-Gorges reservoir along with the analysis on the factors resulting in the valley eutrophication such as the ratio between TP and TN, reservoir-operated circumstances, the weather in the reservoir area, hydrological status and the water quality. The current concentrations of TP and TN which would lead valley eutrophication can be the references for further study and prediction on valley eutrophication in the reservoir area. Based on complexity theory, environmental conditions and some typical mathematical models of nonlinear evolution for describing pollution, two nonlinear ecological dynamic models were established through cell mapping theory and algorithm to describe the rules of valley eutrophication transferring and evolving with the time and the space. And by them we could study effectively the pathway of evolution and transferring, the structure and global dynamic behavior of eutrophication pollutants in the valley above. The emulation computing and analysis of global behaviors, evolution process, structure status, domain of attraction, characteristics of attractors, symmetry of track, comparability with itself and stability of nonlinear eutrophication polluting dynamics systems are studied using the cell mapping method. And a theoretical base was put forward to describe the statuses of pollutants such as attracting, diffusing, distributing and evolving, and to estimate and to predict the pollutants behaviors of the simulative valley system. The results show that the introduction of cell mapping theoryand the corresponding emulation algorithm can offer us a new kind of idea and the technology for studying the dynamics behaviors of environmental pollution and the strong nonlinear complexity dynamics systems for polluted water area in Three-Gorges reservoir. Finally, based on a continuous cultivation model of microbes with continuous nutrient injection in a nutrition box, the dissipation theory and the method of complexity science, a new nonlinear nutrient dynamic model is established which would be more similar to the reality of the valley system. By comparing the cell mapping simulating result of emulating dynamic model and the ratio of TP and TN monitoring data of a stretch of the partially-eutrophied Wujiang river, we have found a direct quantitative relationship between the dramatic shape change of strange attractor of the dynamic model in cell space and algal blooms. This, we could reveal and find these inner chemical affecting factors and environmental evolution rules of the eutrophication process in Three-Gorges Valley...