| 引用本文: | 伍中航,孙海龙,冯镜洁,李然,任爽,袁雨亮.连续水闸对河流COD容量的影响.湖泊科学,2023,35(1):216-223. DOI:10.18307/2023.0115 |
| Wu Zhonghang,Sun Hailong,Feng Jingjie,Li Ran,Ren Shuang,Yuan Yuliang.Influence of continuous sluices on river water environmental capacity of COD. J. Lake Sci.2023,35(1):216-223. DOI:10.18307/2023.0115 |
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| 连续水闸对河流COD容量的影响 |
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伍中航, 孙海龙, 冯镜洁, 李然, 任爽, 袁雨亮
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四川大学水力学与山区河流开发保护国家重点实验室, 成都 610065
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| 摘要: |
| 水闸建设对河流产生阻隔作用,改变了河段水流形态,污染物输运及水质时空分布也随之发生改变,进而可能对水环境容量产生影响。本研究以拉萨河城区段为研究对象,考虑水闸建设对水动力学条件的影响,在利用平面二维模型进行水动力-水质模拟的基础上,计算分析了水闸建设前、后COD的水环境容量,探讨了连续水闸建设对河流水环境容量的影响。研究成果表明,水闸修建对水环境容量的影响主要有两个方面:一是水闸蓄水后,水体由流动转变为相对静止的状态,闸前水流流速减缓,水深增加,影响污染物的扩散,降低污染物降解系数,进而影响污染物降解过程;二是水闸蓄水会使污染物在库区滞留,使污染物滞留时间增加,从而提高污染物的降解量。拉萨河水闸修建后,因水闸蓄水影响,流速减缓,污染物向河道中央扩散受阻,易聚集于排污侧;与天然河道相比,蓄水区河段平均流速由0.34 m/s下降至0.10 m/s,平均水深由0.6 m增大至2.0 m,COD降解系数由0.12 d-1下降至0.04 d-1,下降约67%,污染物滞留时间增大为原来的3倍左右。计算结果表明,在两种影响的综合作用下,1个水闸使研究河段COD容量下降约2.2%,2个水闸共同作用使COD容量下降约9.9%,3个水闸共同作用使COD容量下降约12.3%。整体来看,连续水闸对河流水环境容量产生了一定影响,水闸数量越多,对水环境容量的影响越大。 |
| 关键词: 水环境容量 水闸 降解系数 水质 拉萨河 |
| DOI：10.18307/2023.0115 |
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| 基金项目:国家自然科学基金项目(52039006,U2240212)资助。 |
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| Influence of continuous sluices on river water environmental capacity of COD |
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Wu Zhonghang, Sun Hailong, Feng Jingjie, Li Ran, Ren Shuang, Yuan Yuliang
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State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu 610065, P. R. China
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| Abstract: |
| The sluice construction has a blocking effect on river, which changes the flow pattern, the transport of pollutants and the temporal and spatial distributions of water quality, hence may have an impact on the water environmental capacity. In this study, the urban section of the Lhasa River is taken as the research case, and the influence of sluice construction on hydrodynamic conditions has been studied. On the basis of hydrodynamic and water quality simulations of two-dimensional model, the water environmental capacity of COD before and after sluice construction is calculated and analyzed, and the influence of continuous sluice construction on river water environmental capacity is discussed. The results show that there are two main aspects of the influence of sluice construction on water environmental capacity. First, once sluice stores water, the water body changes from flowing to relatively static state, the flow velocity in front of sluice slows down, the water depth increases; these affect the diffusion of pollutants, reduce the degradation coefficient of pollutants, and then affect the degradation process of pollutants. Second, sluice storage makes pollutants stay in the reservoir area, so that the retention time of pollutants will be increased, which leads to the increase of degradation of pollutants. After the construction of the Lhasa River sluices, due to the influence of sluices water storage, the velocity of pollutants is slowed down, and the diffusion of pollutants to the central part of the river is hindered, which allows pollutants to easily accumulate on the sewage-draining side. Comparing with the natural river, the average flow velocity in the sluice storage area decreased from 0.34 m/s to 0.10 m/s, the average water depth increased from 0.6 m to 2.0 m, and the COD degradation coefficient decreased from 0.12 d-1 to 0.04 d-1 (about 67% decrease), and the pollutant retention time increased by about three times. The calculation results show that, one sluice reduces the COD capacity by about 2.2%, two 9.9%, and three 12.3%. Overall, the continuous sluices have certain impacts on the river water environmental capacity. The more sluices, the greater the impacts on the water environmental capacity. |
| Key words: Water environmental capacity sluice degradation coefficient water quality Lhasa River |
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