臺灣上游湍流河道之輸砂模式研究

A Study on Sediment Transport Models for Torrential streams in Taiwan

何智武(C. W. Ho) ； 黃宏斌(H. P. Huang)

《中華水土保持學報》 14卷1&2期 (1983/12) Pp. 95-106

https://doi.org/10.29417/JCSWC.198312_14(1_2).0008

摘要

當人類活動發展至坡地，尤其對於土地面積有限之台灣、日本及菲律賓等國，具陡坡、粗顆粒沈特滓性之山區河川輸秒量控制問題將益形重要。惟直至目前爲止，大部份之文獻均探討緩坡細顆粒之河川輸砂特性，甚少涉及陡坡粗顆粒者。據此，本文乃首先提出在F（福祿數》＞ 1,S。，（渠槽坡度）= 0.01〜0.10及D（沈滓粒徑》2〜25 mm，即陡坡粗顆粒之渠槽試驗條件下所導出之一組輸砂量模式，其無維度模式為　方程式略　其中，q，q_c及q_s依次為單位寬度渠槽之流量、起動流量及沈滓運移量，g爲重力加速度爲，S_0為渠槽坡度，D爲沈滓粒徑，D_g爲無維度粒徑參數，卽D_g ≡ D /〔V^2 / g（p_s./p-1）〕^(1/3)，其中v爲水之運動粘滯度，p及p_a。分別爲水及沈滓質量密度。此外，亦導出無維度型之阻抗係數模式爲　方程式略　其中，n_b，爲曼寧底床糙率係數，h爲水深，其餘符號之意義與前同。以上模式，經由環境類似於試驗條件之本省蘭陽溪上游圓山溪野外資料修正結果，求得以代表粒徑D_(20)表示之輸砂量修正模式爲　方程式略　另與前者相對應，但改用福祿數F表示之曼寧係數修正模式爲n_b = 0496h^(1/6) F^(0.26)以上模式僅為初步研究所得之結果，日後尚待更完整之試驗資料以擴充其控制參數之範圍，以及更豐富之野外資料以進一步修正其模式，使其更具實用性。

並列摘要

Control of sediment discharge in mountainous streams, where slope is steep and sediment is course, is becoming increasingly important as human activities advancing towards upland areas, especially in those countries such as Taiwan, Japan and Philippine, etc., with limited land size. Up to now, the most literature with studies on sediment transport in rivers have small slope and fine sediment, but relatively few on steep streams with coarse sediment can be found. In the present study, therefore, we first propose a pair of experimental models of sediment discharge in steep channels with coarse sediment obtained from laboratory experiments under the conditions of F (Froude number). 1, S. (channel slope)- 0.01-0.10 and D (sediment size) 2 -25mm. The models in dimensionless form are as follow: (The equation is abbreviated) where q, qc and qs are the water discharge, critical discharge and sediment discharge per unit width, respectively, g is the gravitational acceleration, S_0, is the channel slope, D is the sediment diameter, Dg is the dimensionless sediment size parameter defines by Dg = D/[v/g (p_s/p-1)]^(1/3), in which is the kinematic viscosity and p, p are the mass densities of water and sediment, respectively. At the meantime, we also obtain the dimensionless resistance factor model. to be (The equation is abbreviated) where N_b is the Manning's roughness coefficient for channel bed, h is the water depth and the other notations are the same as above. Finally, the above models have been modified by the field data obtained from Yuan-shan stream the upstream of Lan-Yang stream, with similar environmental condition as the laboratory, in order to make the models applicable to the mountainous streams which possess torrential condition. The modified models of sediment discharge in terms of D are as follows: (The equation is abbreviated) And the corresponding resistance model fro use in field in term of Froude number F is N_b = 0.0496 h 1/6 F^(0.26) However, more investigations should be carried out in the future to expand the range the governing parameters or to modify with more field data.