岷江干流东风岩枢纽水质模拟预测研究

Study on Water Quality Simulation and Prediction of Dongfengyan Junction on the Main Stream of Minjiang River

水库建成运行后水文情势的变化将对水质产生影响,东风岩枢纽库区及坝址下游均有水源保护区,利用MIKE21软件进行对流-扩散水质模型预测水质变化趋势,为库区及水源地水质保护、环境保护对策措施的拟定提供科学依据。计算结果表明:建库后,东风岩坝址处、坝址以上岷江干流、坝下断面以及支流沫溪河COD与氨氮二个指标均满足《地表水环境质量标准》(GB3838—2002)的Ⅲ类以上标准,涌斯江河段入河污染物浓度有所降低,水质较现状略有改善,但改善并不明显,COD指标仍然超标。

After the completion of the reservoir, changes in the hydrological situation will have an impact on water quality. There are water source protection areas in the Dongfengyan Junction Reservoir area and downstream of the dam site. The convection-diffusion water quality model is used to predict water quality change trends using the MIKE21 software for the reservoir area and water source. The formulation of groundwater quality protection and environmental protection countermeasures provides a scientific basis. The calculation results show that: after the construction of the reservoir, the COD and ammonia nitrogen indexes at the Dongfengyan dam site, above the dam site, the main stream of the Minjiang River, the cross section of the dam, and the tributaries of the Moxi River meet the Surface Water Environmental Quality Standard (GB3838-2002) of grade Ⅲ or above. The concentration of pollutants entering the river in the section of the Yongsi River has decreased, and the water quality has improved slightly compared with the current situation, but the improvement is not obvious, and the COD index is still beyond the standard.