| 引用本文: | 韦向星,沈智敏,黄永国,等.龙开口电站库区悬移质形貌及氧化物时空分布特征研究[J].灌溉排水学报,2026,45(10):123-131. |
| Wei Xiangxing,Shen Zhimin,Huang Yongguo,et al.龙开口电站库区悬移质形貌及氧化物时空分布特征研究[J].灌溉排水学报,2026,45(10):123-131. |
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| 摘要: |
| 【目的】揭示汛期悬移质泥沙形貌与氧化物迁移的协同演化机制。【方法】基于2022—2025年龙开口电站库尾、坝前及下游尾水3个断面的水文监测数据与悬移质样品，运用扫描电子显微镜（SEM）、X射线荧光光谱（XRF）及主成分与正定矩阵因子分解法（PCA-PMF）模型，分析不同枯水期与汛期、采样深度及粒径条件下悬移质的微观形貌特征与SiO2、Al2O3、Fe2O3、K2O、CaO组分的时空分布及来源。【结果】①悬移质颗粒形貌呈显著的季节性变化与垂向分异，枯水期颗粒粗大、棱角分明，汛期细化并形成多孔絮状集合体；随着采样深度的增加，颗粒磨圆度降低，棱角趋于显著。②氧化物量总体表现为汛期高于枯水期，且随采样深度与粒径增大而上升，二者对SiO2与Na2O量存在显著的耦合效应，在深度1.6 m、粒径14 μm时达到峰值。③PCA-PMF源解析结果表明，SiO2、Al2O3、Fe2O3、K2O、Na2O、CaO和MgO主要来源于4类输入源，其中，K2O与Fe2O3在第3主成分中呈同源趋势。④构建的SiO2与Na2O量预测模型决定系数（R2）分别为0.85与0.90，粒径对氧化物量的影响程度远高于流量，是控制氧化物迁移的主导因子。【结论】悬移质颗粒形貌与氧化物迁移在汛期过程中表现出显著的协同演变规律，粒径是调控氧化物量的关键变量。建议在库区及引水口前端配置粒径调控设施，以降低超标氧化物迁移风险，保障流域水质安全与水电设施稳定运行。 |
| 关键词: 悬移质 颗粒形貌 氧化物迁移 协同机制 PCA-PMF模型 |
| DOI：10.13522/j.cnki.ggps.2026110 |
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| Effects of flooding on suspended-sediment characteristics and oxide transport in Longkaikou Reservoir |
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Wei Xiangxing, Shen Zhimin, Huang Yongguo, Gao Zhiguo, Li Jiayu1, Ran Ling, Du Min
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1. Huaneng Longkaikou Hydropower Co., Ltd., Dali 671505, China;
2. Yunnan Fangyuan Technology Co., Ltd., Kunming 650109, China;
3. Kunming University of Science and Technology, Faculty of Civil Engineering and Mechanics, Kunming 650500, China
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| Abstract: |
| 【Objective】Flood events can alter suspended-sediment characteristics and the transport of sediment-associated oxides, potentially affecting watershed water quality and the operation of reservoirs and hydropower facilities. Here, we studied the co-evolution of suspended-sediment morphology and oxide transport during the flood season in the Longkaikou Reservoir.【Method】The study was based on hydrological data and suspended-sediment samples collected from 2022 to 2025 at three sections of the reservoir: the outlet, upstream of the dam, and downstream of the outflow. The microstructural characteristics of suspended sediments with different particle sizes sampled at different depths under both base-flow and flood conditions were characterized using scanning electron microscopy (SEM) and X-ray fluorescence spectroscopy (XRF). Principal component analysis (PCA) and positive matrix factorization (PMF) were used to identify potential sources of SiO2, Al2O3, Fe2O3, K2O, Na2O, CaO and MgO.【Result】①The morphology of suspended sediment particles varied significantly with season and sampling depth. During the dry season, sediment particles were relatively coarse and angular, whereas during the flood season, they became finer and formed porous, flocculent aggregates. With increasing sampling depth, particle roundness decreased, while angularity increased. ②Overall, oxide concentrations were higher during the flood season than during the dry season and increased with sampling depth and particle size. Sampling depth and particle size significantly affected SiO2 and Na2O concentrations, which reached their maximum values at a depth of 1.6 m and a particle size of 14 μm. ③PCA and PMF analysis indicated that SiO2, Al2O3, Fe2O3, K2O, Na2O, CaO, and MgO were primarily associated with four potential sources, with K2O and Fe2O3 exhibiting a common source contribution in the third principal component. ④The predictive model for SiO2 and Na2O concentrations was accurate, with their R2 values being 0.85 and 0.90, respectively. Sediment particle size had a greater influence on oxide concentrations than flow rate and was the dominant factor controlling oxide transport.【Conclusion】The morphology of suspended sediment particles and oxide transport were closely coupled during the flood season, with particle size being the key factor regulating oxide concentrations and migration. These findings suggest that managing sediment particle sizes in reservoir areas and upstream of water intakes can help reduce excessive oxide transport and safeguard watershed water quality and the operation of hydropower facilities. |
| Key words: suspended matter particle morphology oxide migration synergistic mechanism PCA-PMF model |
