植生護岸渠道粗糙係數之研究

Study on Roughness Coefficient of Vegetated Channels

楊紹洋(Shaw-Yang Yang) ； 邱金火(Jin-Forie Chiou) ； 洪偉哲(Wei-Jhe Hong)

《中國土木水利工程學刊》 20卷2期 (2008/06) Pp. 197-204

https://doi.org/10.6652/JoCICHE.200806_20(2).0004

摘要

本研究以生態渠道為題，考慮渠道護岸植生或野草入侵下，探討渠道的粗糙係數。以人造草皮模擬渠道護岸植生，進行植生護岸之渠槽試驗，分析渠道之水理特性。研究結果顯示，於相同渠坡時，流量Q=0.0305cms植生護岸之曼寧係數n(下標 w)值為最大；於相同流量時，渠坡S=0.025植生護岸n(下標 w)值為最小。在低流量時n(下標 w)值變化大於高流量結果，此時n(下標 w)值受渠坡的影響較大。植生護岸n(下標 w)值與D/B（水深／渠寬）和VR(下標 w)（平均流速×水力半徑）之關係，經臨界流況漸近線分析得，護岸n(下標 w)值約為0.0600。由線性迴歸分析得n(下標 w)=0.0800N(下標 F)^2-0.2140N(下標 F)+0.1961和n=-27.5350n(下標 w)^2+5.0767n(下標 w)-0.1661。此研究成果有助於植生護岸n(下標 w)值之推估，以及生態工程實務之應用。由多元迴歸分析得，植生護岸n(下標 w)值的關係函數為n(下標 w)=0.0614(D/B)^(-0.1452)(S)^0.0454(N(下標 F))^(-1.0782)，在已知水理條件下，此函數可有效估算植生護岸之粗糙係數，提升生態工程水理設計引用之便利性。

關鍵字

生態工法 ； 渠槽試驗 ； 植生渠道 ； 曼寧係數 ； 多元迴歸分析

並列摘要

This research concerns with the ecological channel. The channel roughness coefficient under the circumstance with vegetated revetment, or weeds invasion is considered, and the according hydraulic test is done. The vegetated revetment channel is simulated by an artificial sod, and the hydraulic characteristic is analyzed. The results show that with the same channel slop S and flow rate Q=0.0305 cms, Manning's coefficient of vegetated revetment (n(subscript w)) is the largest; with the same flow rate and S=0.025, Manning's coefficient of vegetated revetment (n(subscript w)) is the smallest. The effect of n(subscript w) value is larger at the lower flow rate than that at the higher flow rate. From the analysis of the relation between n(subscript w) and (D/B) / or VR(subscript w) for N(subscript F)=1, the n(subscript w) value is close to 0.0600. Applying the linear regression analysis, one can obtain n(subscript w)=0.08N(subscript F)^2-0.214N(subscript F)+0.1961 and n=-27.535n(subscript w)^2+5.0767n(subscript w)-0.1661. The results provide the estimation of vegetated revetment n(subscript w) and encourage the application of ecological channel works. From the multiple regression analysis, the function of Manning's coefficient for the vegetated revetment can be obtained as n(subscript w)=0.0614(D/B)^(-0.1452) (S)^0.0454 (N(subscript F))^(-1.0782). Under the known hydraulic conditions, this function can estimate effectively the roughness coefficient of the vegetated revetment. In addition, it can promote the hydraulic design of the ecological channels.

並列關鍵字

ecological engineering methods ； channel test ； vegetated channel ； Manning's coefficient ； multiple regression analysis