| 引用本文: | 何娟,郑珊,吴保生.三门峡水库冲淤重心变化及其对潼关高程的影响.湖泊科学,2023,35(1):338-348. DOI:10.18307/2023.0126 |
| He Juan,Zheng Shan,Wu Baosheng.Changes of erosion/deposition centers in the Sanmenxia Reservoir and its influence on the riverbed elevation at Tongguan. J. Lake Sci.2023,35(1):338-348. DOI:10.18307/2023.0126 |
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| 摘要: |
| 以往关于三门峡水库的研究多关注库区年际间的冲淤变化,而对汛期和非汛期库区冲淤分布研究较少。本文基于三门峡水库蓄清排浑运用以来1974—2018年实测水沙、断面及冲淤数据,研究汛期和非汛期库区冲淤重心的迁移、冲淤速率及其对潼关高程的影响。结果表明,蓄清排浑运用以来库区河道基本遵循汛期冲刷、非汛期淤积的演变规律。分别定义汛期最大冲刷速率和非汛期最大淤积速率发生的相邻两断面间的子河段为冲刷重心和淤积重心,汛期冲刷重心与非汛期淤积重心出现的位置基本对应,1974—2010年冲淤重心由距坝约90 km逐渐向坝前移动,平均下移速率约1~2 km/a;2010年后冲淤重心逐渐上移,2017年位于坝上游约60~70 km,但冲淤强度明显减弱。淤积重心的位置主要受水库回水长度影响,冲刷重心主要与汛期水流能量相关,淤积重心位置迁移滞后于影响因子的变化约5年,而冲刷重心滞后时间约2年。潼关高程与潼关至太安段(潼太段)比降呈反比关系,比降越大,潼关高程越低,而当冲刷重心迁移至潼太段并影响其下段时,潼太段比降增大,利于潼关高程降低。1985年后回水范围和冲淤重心均位于潼关以下,潼关高程受冲淤重心影响较小。 |
| 关键词: 三门峡水库 冲淤重心 回水长度 汛期水流能量 潼关高程 |
| DOI：10.18307/2023.0126 |
| 分类号: |
| 基金项目:国家自然科学基金项目(U2243218,52079095)资助。 |
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| Changes of erosion/deposition centers in the Sanmenxia Reservoir and its influence on the riverbed elevation at Tongguan |
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He Juan1, Zheng Shan1, Wu Baosheng2
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1.State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072, P. R. China;2.State Key Laboratory of Hydroscience and Engineering, Tsinghua University, Beijing 100084, P. R. China
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| Abstract: |
| Previous studies on Sanmenxia Reservoir mostly have been focused on the interannual degradation and aggradation changes, while there were few studies on the erosion and deposition distributions of the reservoir area during flood/non flood seasons. Identifying the erosion/deposition centers (sub-reach with greatest adjustment rates during flood/non flood seasons), the migration of erosion/deposition centers in the reservoir area and their rates and influences to the changes of the riverbed elevations at Tongguan during flood/non flood seasons were analyzed based on the data of water discharges, sediment loads, and erosion/deposition volumes after the controlled releases of “storing the clear water during the non-flood seasons and discharging the turbid water during flood seasons” in the period of 1974-2018. Results showed that the reservoir was generally degraded during the flood seasons and aggraded during the non flood seasons, and the erosion/deposition centers generally migrated correspondingly. The erosion/deposition centers had migrated downstream with an average rate of about 1-2 km/a at 90 km away from the dam before 2010 and then moved upstream at 60-70 km in front of the dam in 2018 with significantly weakened erosion/deposition rates. There is a strong positive correlation between the river kilometer (RKM) of the erosion center from the dam and the 2-year exponential weighted average value of flow energy during the flood seasons. So did the RKM of the deposition center and the backwater length with 5-year exponential weighted average value. The riverbed elevations of Tongguan are negatively correlated with the bed slope of Tongguan-Tai'an Reach which means the greater the gradient, the lower the riverbed elevation of Tongguan. The channel slope of Tongguan-Tai'an Reach increased easily and the riverbed elevation of Tongguan decreased when the erosion center was located at the downstream of the Tongguan-Tai'an Reach. When Tongguan was out of the backwater area and the erosion/deposition centers were also located below the Tongguan-Tai'an Reach after 1985. During this time, the riverbed elevations of Tongguan had been less affected by the erosion/deposition centers. |
| Key words: Sanmenxia Reservoir erosion/deposition centers backwater length flow energy during flood seasons riverbed elevation of Tongguan |
