受潮汐影响的断头河道活水工程的设计与运行

Design and Operation of Water Flowing Project of the Truncated River with Tidal Influence

C河是受潮汐影响的断头河道,上游无洁净水源补给,路涵阻水效应导致河道洼地存水长期滞留,富营养化特征明显。C河是H岛上A河的支流,A河横贯H岛,西接B河。结合H岛水系特点及A河、B河活水方案,在A河设置活水泵站,经800 m压力管道输送至C河末端,出水口采用景观跌水,活水的同时增加水体溶解氧。活水工程实施后,C河DO浓度为2. 2～9. 3mg/L,氨氮浓度为0～1. 0 mg/L,COD_(Mn)浓度为5. 4～11. 6 mg/L,BOD_5浓度为3. 7～7. 2 mg/L,主要监测指标均满足《地表水环境质量标准》(GB 3838—2002)Ⅴ类标准,基本达到与A河同质的水平,透明度达到60～100 cm,有效改善了河道水质和感官指标。

The River C was a truncated river with tidal influence. There was no clear water supply in the upstream. The road culvert hindered the water and caused long-term retention of water in the river,which could lead to eutrophication. The River C was a tributary of the River A on the Island H. The River A runed across the Island H and the west reached the River B. Combined with the characteristics of the Island H water drainage and the water flowing schemes of River A and B,a pumping station was set up in River A,and the water was transported to the end of River C through the 800 m pressure pipeline.The water outlet adopted the landscape water drop zone,which increased the dissolved oxygen in the river while water flowing. After the implementation of the water flowing scheme,DO was kept between 2. 2-9. 3 mg/L,NH3-N between 0-1. 0 mg/L,CODMn between 5. 4-11. 6 mg/L and BOD5 between 3. 7-7. 2 mg/L. The main monitoring indicators met the Class V standard of Environmental Quality Standards for Surface Water (GB 3838-2002),basically reached the level of homogeneity with River A,and the transparency reached 60-100 cm,effectively improved the river water quality and sensory indicators.