MSc research [Modeling of water quality in Taihu Lake, China]

Nowadays, Taihu Lake in China has been facing serious water quality problems. Water quality in Taihu Lake is worse than Class V as per Chinese "Surface water quality standard". One particular water quality problem of Taihu Lake is the green algae bloom presence, which usually happens during spring and autumn every year. Since 2007 when Wuxi's "Water crisis" took place (large amounts of green algae blocked the water intake, people around Wuxi city suffered in getting fresh water during 2007), the Chinese government has taken measures to address the water quality problems in Taihu Lake. Present study investigated possible solutions to address water quality problems of Taihu Lake. The tool used to test effectiveness of the proposed possible solutions is Delft3D. Definition of possible solution is done based on data made available by Taihu Basin authority. Four alternatives including 14 cases are proposed as solution for improving water quality in Taihu Lake. Nine criteria were defined for evaluation of the proposed alternatives. These criteria were mainly selected based on the type of output results offered by the model. Multi-criteria-analysis methodology is used for the evaluation of the alternatives. Different weights are assigned to the selected criteria, depending on their importance, in order to see the performance of the 14 proposed solutions. A previously existing Delft3D model on Taihu Lake is used for the present research. This model describes the hydrodynamic state of Taihu Lake and it is coupled with the Delft3D WAQ model to represent water quality of the lake. The water quality component of the model contains description of 44 substances. That gives results on concentration of important elements describing the eutrophication status of the lake, such as total nitrogen, total phosphorus, and green algae. The results include the most and least advisable alternatives and the difference between them when dealing with water quality problems. The score for each criterion can be seen in the evaluation chart. The alternative with best score using a smallest amount of cost is also developed. This is able to provide basis for the treatment of water quality problems in Taihu Lake. From the evaluation, the best alternative is "Draining and diversion engineering construction". It diverts water from the Yangtze River and open river channels around Taihu Lake. The result from this research is not implemented or realized. It is provided as a suggestion on how to carry out the study on finding adaptation measures when addressing water quality problems