Delft3D-Based Modeling On HuLun Lakewater Quantity And Quality Model

Lakes are one of the cradle of all livings on prairies. It is one of the important sources to maintain water supply to local residents and the ecological water demand of the surrounding ecological environment. It is also one of the important factors that restricts the social stability and economic sustainable development. Because of the lakes are located in open terrain, higher elevation, and higher latitude region with windy climate features and strong evapotranspiration,lakes on the prairies are ecological vulnerability lakes, the water quality in different periods vary as well. In the recent years, the lakes were shrinking gradually and the water quality was getting worse because the effects of the global warming, uneven precipitation, and the economic and social development. As a result of this, water resources shortage had become one of the factors that seriously restricted the sustainable development of loeal society. More and more attentions had been focused on scientific management and utilization of water resources.Hulun Lake is located at the junction of three countries, Russia, Mongolia, and China, in the southeast of the largest inland port, Manzhouli. The water quality and quantity are so important to the local social and economic development that especially the change of its quality should be scientifically investigated and managed. The water quality change very much depends on the lake hydrodynamic condition.But the hydrodynamic datas of Hulun Lake is rare. The water quality of the lake past three years was investigated. Delft3D was applied to model the change of water quality in the lake in order to provide a scientific and reliable approach for protection and improvement of the local ecological environment. The results showed that the water quality of the most lake open water area was classified as V and Worse V. Principal Component Analysis (PCA) showed that principal components changed with time. Water temperature, total nitrogen, and dissolved oxygen were the principal components in July and phosphorus salt, water temperature and pH were the principal components in September. The whole lake open water area could be claasified into different water quality characteristic areas. There were four categories that could be clustered in July, A10, and D7 belonged to the same categorie, D11, E8, and F5 the same, G2, H3, and 12 the same, and F9, G8 the same respectively, in September B9, D7, G2, and 12 belonged to the same categorie, E8, F5, G8, H3,15, and F9 the same respectively.The main factors like heavy metals (As) and chemical oxygen demand (COD) were used to build up the water environment dynamic model in the lake. The results showed that hydrodynamic condition along the lakeshore delt was better than that in the center area. Some areas had higher varition of water level like Wudoulu fishing area, Xiaohekou, and Shuangshanzi fishing area. The water in the northern area of the lake was more polluted with high plutant load than that in the southern area.