水庫洩降沖刷試驗與模擬

本研究乃對水庫洩降沖刷進行研究，以期能提供一清淤之參考。研究中進行三組洩降排砂試驗，考慮不同的水庫底床淤積型態，探討分析洩降排砂時庫區水位、淤積砂面變動及出庫排砂量之變化，並將試驗量測資料與四種不同輸砂公式所推導得出之擴散模式，經數值模擬做一比較分析。數值模式模擬結果以Smart輸砂公式推導得出之擴散模式，所計算洩降沖刷時砂面變化與出庫排砂量之結果較佳。

關鍵字

洩降沖刷；擴散模式；出庫排砂量

並列摘要

Drawdown flushing can be a rather useful approach to reduce sediment accumulation in the reservoir. The basic concept of drawdown flushing for excavating sediment deposit is to lower the water stage of the reservoir. Experiments are conducted in a 12 m-long flume with the glass side walls to study the drawdown flushing controlled by the sluice gate for understanding the influence of the water stage and bed elevation changes. The channel bed slope and the depositional pattern are discussed. Based on experimental data, four diffusion models are derived and established by different sediment transport equations for predicting bed profile variations as well as outflow sediment discharges. Among these four diffusion models, the model based on Smart sediment transport equation has performed better simulation than others.

並列關鍵字

Drawdown flushing ； Diffusion model ； Outflow sediment discharge

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