運用橫向堆石群改善溪流生態棲地之試驗研究

Experimental Study of Improving River Habitat By Lateral Stones Colonies

林秉賢(Bing-Shyan Lin) ； 連惠邦(Hui-Pang Lien) ； 葉昭憲(Chao-Hsien Yeh)

《中華水土保持學報》 33卷4期 (2002/12) Pp. 317-326

https://doi.org/10.29417/JCSWC.200212_33(4).0007

摘要

本試驗研究透過不同間距的橫向堆石群配置，觀察在不同流況及坡降條件下，直線渠道之床面幾何變化、流況歧異度變化、河床穩定性變化以及水體再曝氣能力的影響，以探討橫向堆石群對溪流棲地環境改善之功能。研究結果發現橫向堆石群的設置可增加試驗區水深，並使相對流速與福祿數減小，當配置間距為河寬之2至4倍時，所產生的河床與水流型態最富變化，且其再曝氣能力相對值亦為所有試驗條件中之最大者。此外，在渠床坡降1度且堆石間距為4倍河寬之試驗條件下之河床較其它試驗條件來得穩定。總結試驗成果，在考慮多樣化的流況條件與維持適當的床面泥沙穩定度與水體再曝氣能力條件下，建議以床面坡降1度及4倍河寬為橫向結構物的配置間距，可有效塑造較多樣化的水流流況，以營造適合多種不同水生生物的棲地流況環境。

關鍵字

試驗研究 ； 橫向堆石群 ； 溪流棲地

並列摘要

With different intervals of lateral stone colonies under diverse conditions of flow and channel bed form within straight channels, this study tried to discover the relationship between the structural arrangement and stream habitat responses, i.e., change of erosion dimension, change of flow diversity index, channel bed stability, and water dispose ability, for finding the best river habitat environment form by this type of structural approach. Various findings from experimental results were concluded. Lateral stone colonies are capable of increasing flow depth of observatory sections and decreasing relative velocity and Froude number. With interval set as 2 to 4 times of channel width, the biggest changes in water level and bed forms were found. With l-degree bed slope and interval of 4 times relative bed width, the channel bed stability and water dispose ability were the biggest for those of experimental conditions in straight channel. Over all, to achieve the goals of forming the biggest changes in bed form and flow and keeping the best channel bed stability and water dispose ability, the experimental results of this study implied that, at straight lateral stone colonies with interval of 4 times relative channel width and 1 degree bed slope can effectively form the best river habitat environment.

並列關鍵字

experimental study ； lateral stones colonies ； river habitat