Research On Water Quality Prediction In Banduoyiji,Banduoerji And Yangqu Reservoir In Huanghe

Banduoyiji, Banduoerji and Yangqu hydropower stations are important component for development of upper yellow river cascade hydroelectric power station. The main role of this channel segment development is hydroelectric power generation, which the social economic conditions and the characteristic of channel segment and landform and geology bases on upper reaches area of yellow river. The completion of reservoir will change hydrological situation and hydro-environ conditions in the reservoir area, further exerting an important effect upon ecology, farmland irrigation and living water use. ect. For this reason, water quality prediction is an important part of environmental impact assessment before the construction of hydropower station. Prediction of water quality in the reservoir before its construction, is of great significance of environ protection and construction, operation for the project.According to the characters of Banduoerji and Yangqu reservoirs, the longitudinal one-D dynamic water quality model is built in this paper, and the model is simplified. After the simplification, the number of parameter in the model is lesser, it can be solved easier, and the wanted data are lesser. The model is validated by the measured data of water quality in the river, and the relative error is minor. In this paper, the longitudinal change and vertical distribution of organic pollutant is predicted in the Banduoyiji reservoir after its completion, which by establishing vertical false two-D water quality model, some problems existing vertical two-D model such as the difficult solve and disposal are overcame. In the case of without similar reservoir data, the predecessor research outcomes are used for reference, then determine degradation coefficient, longitudinal dispersion coefficient and vertical turbulent diffusion coefficient in the paper.According to existing water quality at present, the organic pollutant water quality index (BOD₅) is chosen as prediction object. The water quality in Banduoyiji, Banduoerji andYangqu reservoirs are predicted by utilizing the two models which are built above.The prediction results indicate: (1) the completion of reservoir will increase hydraulic detention time, which will be advantage of organic pollutant sink. (2) In the three typical years, water quality in low flow year will be the worst, the difference of water quality in high flow year and moderate flow year will be minor. (3) In one year, water quality in rainy period will be the worst, there has a relation with area pollution, as the upstream reservoir adjusting action, water quality in low flow period and moderate flow period will has little difference. (4) there is high pollution in water quality low flow year, even though, all the time concentration will belong to the range of Group â…  water, the moderate flow year lower and high flow year worst. (5) the upper flow and area pollution are the main pollutant source, so pollution control and harness in the river basin should be strengthened.