Research On Geo-Environment And Control Mechanism Of Eutrophication In Chaohu Lake

Considering the insufficient basic researches on the control of eutrophication in Chaohu Lake, a systematical study for the control mechanism of lake eutrophication was conducted from the viewpoint of uncertain information, and several novel computing models and assessment methodologies were provided in the thesis. Results and conclusions drawn in this thesis can be summarized as follows:1. Based on the fuzziness, impreciseness and randomness of water environmental system, fuzzy arithmetic is utilized to simulate the fuzzy and imprecise relations in water quality modeling for rivers surrounding the Chaohu Lake.2. From the concomitancy of randomness, fuzziness, grey property and unascertainment of water environmental system, blind number theory in unascertained mathematics was applied for the calculation of water environmental carrying capacity in shallow lakes. On these grounds, a novel model with blind parameters, suitable for large and shallow lakes, was established for water environmental carrying capacity.3. A blind model for estimating the soil erosion and non-point source pollution loads of absorbed nitrogen and phosphorus was constructed by defining the parameters in traditional USLE model as blind numbers.4. The potential ecological risk analysis for the sediments in the mouth of rivers surrounding the Chaohu Lake, was conducted using unascertained number theory in the thesis. As a case, we concretely studied the potential ecological risk in the estuary of Shiwuli River.5. As for eco-environmental quality assessment of Chaohu Lake basin, two novel methodologies, namely information entropy fuzzy matter-element model and multiple-agent blind model, were utilized, and obtained the same ranks for the eco-environmental quality of Chaohu Lake basin.6. After improving the present Fuzzy-probability model, we attempted to introduce the improved model to the assessment of lake eutrophication. According to the improved model, we drew such a conclusion that Chaohu Lake was in the states from mesotropher to middle eutropher in the year of 2004.7. The ways and measures to control the eutrophication of Chaohu Lake were proposed in the end.