河道隘口作用下土砂調節特性之渠道實驗研究

本文以室內渠道實驗探討天然河道隘口對土砂調節之功能，藉以了解河道隘口對上游來水來砂事件之調節能力。河道隘口對上游來砂事件之儲砂特性，透過隘口比例模型和上游供砂速率調整，分析隘口上游土砂囚砂能力及下游排砂尖峰折減變化，並進一步探討河道隘口束縮比對囚砂率及排砂折減率之關係。實驗結果顯示，(1)不同隘口比例模型參數對於土砂調節能力以束縮比影響最大，而束縮長度影響不顯著；(2)在上游來水來砂條件相同下，隘口束縮比愈大，則隘口囚砂率及隘口下游排砂折減也愈大；(3)在相同束縮比條件下，上游來砂規模愈大，則隘口囚砂效果愈佳，反之，在一般常流水事件中，則隘口囚砂效果不明顯。由研究成果知天然隘口地形在大規模土砂事件時可提供一定程度之囚砂功能及縮減土砂洪峰排出。

關鍵字

隘口；束縮；土砂調節功能；土砂前緣

並列摘要

The flume experiment was conducted to explore the sediment regulating capacity in river notch. Different river notch scale model and sediment supply rate of the experiment is expected to show the sediment trapping and sediment reduction ability of river notch. The flume experiment with control parameters including contraction ratio, contraction length, and sediment supply rate to understand the sediment trapping and peak sediment transport reduction capacity. And the relationship between the sediment trapping rate, sediment reduction rate, and contraction ratio was discussed. The results show that (1) the contraction ratio is more effective than contraction length in sediment regulating capacity; (2) under the same sediment supply condition, the sediment trapping rate and sediment reduction rate increases with contraction ratio; (3) under the same contraction ratio condition, the sediment regulating capacity increases with intensity of sediment supply rate. The results confirmed that the river notch has the ability to trap and reduce the amount of sediment.

並列關鍵字

River Notch ； Contraction Ratio ； Sediment regulating Capacity ； Sediment front

國際替代計量

河道隘口作用下土砂調節特性之渠道實驗研究

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