邊灘倒伏植生排列分布對流場及床型之影響

The Influence of the Flow Field and the Bed Form by Bent Vegetation Arrangements on the Riverside

李津甫(Jin-Fu Li) ； 黃晉揚(Chin-Yang Huang) ； 陳樹群(Su-Chin Chen)

《中華水土保持學報》 47卷2期 (2016/06) Pp. 53-60

https://doi.org/10.29417/JCSWC.201606_47(2).0001

摘要

本研究以室內渠槽進行動床試驗，利用彈性材料之人工植株模擬遭受水流衝擊的倒伏植生，研究不同排列型態之邊灘植生區，對於河川水流作用及底床沖淤之影響。渠槽分為邊灘植生區和主槽無植生區，試驗區總長3 m、寬0.6 m，而植生區的寬度為0.3 m，倒伏植株與床面夾角約為22°。邊灘植生排列分為間隔橫向、間隔縱向、連續橫向及連續縱向等四種配置。試驗結果顯示，連續縱向之倒伏植生流速遞減比最大，水流往主槽無植生區集中之情形最為顯著，主槽沖淤變化情形最為強烈。而間隔橫向種植對床型變化影響較小，具有穩定河床之作用，為較佳的河川管理方式。

關鍵字

灘地植生 ； 床型演變 ； 灘地植生 ； 床型演變 ； 沖積河川

並列摘要

In this study, we used different arrangements of artificial elastic bent vegetation to simulate the influence of flow fields and bed form variation in a mobile-bed laboratory flume. The flume is 3 m long and 0.6 m wide, which is equally distributed along a riverside with vegetation and a main channel without vegetation. The bent angle is 22° between the base of the vegetation and the bed. We made four types of arrangements, including interval transverse, interval longitudinal, continuous transverse, and continuous longitudinal. The results show that the continuous longitudinal arrangement has the highest velocity decrease ratio and directs flow to the main channel, which seriously scours the bed. The interval transverse arrangement has a minimal effect on bed form variation, which leads to better stability. As a result, the arrangement of interval transvers is the best approach to river management.

並列關鍵字

Riverside vegetation ； bed form variation ； fluvial river