Pusan National University, Busan, Republic of Korea.
Green Land & Water Research Institute, Busan, Republic of Korea.
Water Environ Res. 2024 Sep;96(9):e11120. doi: 10.1002/wer.11120.
When an artificial structure is built in a river, the river changes significantly in water quality and hydraulic properties. In this study, the effects of the weirs constructed in the middle section of a river as a four major rivers restoration project in Korea on water quality and hydrological characteristics were analyzed. For multi-dimensional data analysis, a self-organizing map was applied, and statistical techniques including analysis of variation were used. As a result of analysis, the cross-sectional area of the river increased significantly after the construction of the weir compared to before the construction of the weir, and the flow velocity decreased at a statistically significant level. In the case of water quality, nitrogen, phosphorus, and suspended solids tended to improve after weir construction, and chlorophyll-a and bacteria tended to deteriorate. Some water quality parameters such as chlorophyll-a were also affected by seasonal influences. In order to improve the water quality deteriorated by the construction of the weir, it is necessary to consider how to improve the flow velocity of the river through partial opening or operation of the weir. In addition, in order to determine the effect of sedimentation of particulate matter due to the decrease in flow rate, it is necessary to conduct investigations on sediments around weirs in the future. PRACTITIONER POINTS: Compared to before the construction of the weir, there was no significant change in the flow rate of the river after the construction of the weir. In the case of chlorophyll-a and bacteria, the water quality was deteriorated after weir construction. To improve the deteriorated water quality, it is required to consider the fundamental management of each pollutant source and the flexible operation of both weirs. For some improved water quality parameters, further research is needed to determine whether these improvements are directly attributable to the construction of a weir.
当人工结构建在河流中时，水质和水力特性会发生显著变化。本研究分析了韩国四大河流修复项目中在河流中段建造的堰对水质和水文特性的影响。为了进行多维数据分析，应用了自组织映射，并且使用了包括方差分析在内的统计技术。分析结果表明，与建造堰之前相比，堰建成后河流的横截面积显著增加，流速在统计学上显著降低。就水质而言，氮、磷和悬浮物在堰建成后趋于改善，而叶绿素-a 和细菌则趋于恶化。一些水质参数，如叶绿素-a，也受到季节影响。为了改善因建造堰而恶化的水质，有必要考虑如何通过部分开启或堰的运行来提高河流的流速。此外，为了确定因流速降低导致的颗粒物沉降对水质的影响，有必要在未来对堰周围的沉积物进行调查。
与建造堰之前相比，堰建成后河流的流速没有显著变化。在叶绿素-a 和细菌的情况下，堰建成后水质恶化。为了改善恶化的水质，需要考虑对每个污染源进行基本管理以及堰的灵活运行。对于一些水质得到改善的参数，需要进一步研究以确定这些改善是否直接归因于堰的建造。
