圖書典藏及影音數位平台

本計畫係藉由與國內外著名之輸砂學者合作，以臺灣河川泥砂運移特性為案例，擴充建置本土化輸砂公式，並結合現有數值模式，以臺灣5大流域為案例進行河道穩定與流域土砂運移與管理研究。整體工作架構包括臺灣河川基本資料現地補充調查、國際合作研發本土化輸砂公式、及本土化輸砂公式結合數值模式進行應用研究等三大部分。

Steep slope, severe bed change and young geologic texture are the characteristics of Taiwan’s rivers. These characteristics often case huge sediment transport rate which the general common sediment transport formulas have the limit to apply in Taiwan’s river. This study will divide into three years to develop a new sediment transport formula which is suitable for the characteristics of Taiwan’s rivers. The flow and sediment data are surveyed and collected during the floods. These measured data are used to develop a new sediment transport formula, which wll be installed in the numerical model. In this year, Choushui River is selected as the study site. Their calculated sediment transport rates are compared with the measured ones. Then the three top performing formulas are selected as potential candidates for the development of new formula. Two approaches are used to develop the new formula. The first approach will use the top three formulas selected by the review of general common formulas, and recalibrate their coefficients using the collected data. The best performing one is the final formula to be used. The second approach uses the basic theories of sediment transport, including Bagnold’s stream power, Yang’s minimum stream power, diffusion theory, gravitational theory, dimensional analysis, etc. According to Wu et al (2000), the bed-load transport rate is highly related to grain shear stress, and the suspended-load transport rate is highly related to the stream power available in the flow system. In addition, the hiding and exposure mechanism in the nonuniform bed material significantly affect sediment transport and should be taken into account. After comparison, Wu et al. (2000) formula has the best performance in Dajia River and Choushui River.