降雨-波浪-水位对库岸崩滑泥沙空间分布的影响

Effects of rainfall, waves and water levels on the spatial distribution of sediment eroded from reservoir banks

中文关键词: 关键词：降雨  波浪  水位  泥沙分布  模型试验

英文关键词: Key words: rainfall  waves  water levels  sediment distribution  model experiment

中文摘要:

      摘要：库岸崩滑对库区泥沙含量有显著影响，掌握崩滑泥沙与水文因素的关系有助于分析库区泥沙的淤积过程和输移规律。通过模型试验分析了库岸崩滑后降雨、波浪、水位涨落对泥沙空间分布的影响。结果表明：（1）降雨能减弱泥沙含量的变化幅度，促使悬移质泥沙颗粒细化。降雨后含沙量平均变异系数降低22%，极细砂级颗粒含量降低53%。（2）水位上涨能促使离岸方向和水深方向的泥沙含量降低，悬移质泥沙颗粒粗化。离岸方向和水深方向的平均含沙量在水位上涨后方分别降低14%和20%，极细砂级颗粒含量增加15%。（3）波浪可促使离岸方向含沙量增加，含沙量变化幅度降低，其平均含沙量上涨78%，平均变异系数下降了67%。应着重关注水位上涨时库区泥沙的淤积问题。

英文摘要:

      Abstract: Reservoir bank avalanches can significantly influence the sediment content of reservoirs, thus it is crucial to comprehend the relationship between avalanche sediment and hydrological factors to study the depositing process and transport laws of sediment. The present study utilizes model experiments to investigate the effect of rainfall, waves, and water level fluctuations on the spatial distribution of sediment following reservoir bank avalanches. The results show that rainfall plays a significant role in attenuating the magnitude of sediment content variation and refining the particle size of suspended sediment. Specifically, the average coefficient of variation for sediment content decreases by 22% after rainfall, and the proportion of very fine sediment particles decreases by 53%. Water level rise can significantly decrease sediment content in the offshore and water depth directions and effectively increase the coarseness of suspended sediment particles. Specifically, after water level rise, the average sediment content in the offshore and water depth directions decreased by 14% and 20%, respectively, while the very fine sediment grade particles increased by 13%. Waves, on the other hand, can increase the sediment content in the offshore direction, but can also attenuate the magnitude of variation in sediment content. After wave conditions, the average sediment content in the reservoir area increased by 78%, while the average coefficient of variation of sediment content decreased by 67%. The problem of sedimentation in the reservoir area due to rising water levels should be a key concern.