河川與集水區泥砂遞移率之推估研究

Estimating the Sediment Delivery Ratio in Rivers and Watersheds

10.29417/JCSWC.199903_30(1).0005

陳樹群(Su-Chin Chen)；賴益成(I-Cheng Lai)

沖蝕指標模式 ； 泥砂遞移率 ； 河道輸砂 ； soil erosion index model ； sediment delivery ratio ； sediment transport

中華水土保持學報

30卷1期（1999 / 03 / 01）

47 - 57

繁體中文

集水區中之泥砂因受到外力作用而產生沖蝕，搬運及堆積之現象，此可由集水區上游泥砂流失量和出口泥砂産量兩者間之顯著差異來說明。對於集水區之泥砂演算，目前已發展出不少的土壤沖蝕模式及河道輸砂公式來預估集水區之土壤沖蝕量和泥砂產量，而兩者間所存在之差距一般可以集水區泥砂遞移率來加以表示。本研究乃利用空間分佈理論簡易地分析影響坡地泥砂遞移的因子，藉由曾文水庫集水區主流防砂壩淤砂之粒徑資料進行河川泥砂遞移現象之探討，並應用土壤沖蝕指標模式（指標法）進行土壤沖蝕之估算，且針對國內八座水庫進行集水區泥砂遞移現象之研討。研究顯示以指標法推算土壤沖蝕量，配合沖蝕崩坍比例計算泥砂總流失量，再運用SDR公式所推估的集水區泥砂產量與實測值相近。

The surface soil in the watershed is normally eroded, transported and deposited by extrinsic force. This phenomenon can be evidenced by the apparent distinction between the upstream soil erosion and the sediment yield at the basin outlet. Numerous soil erosion models and sediment transport equations have been developed to predict soil erosion and sediment yield in the watersheds, and the relation between them can be expressed by the Sediment Delivery Ratio (SDR). This study analyses the factors affecting the upland sediment delivery by using the spacial distribution theory, the SDR of rivers, and the proportion of soil erosion to landslide derived form the filed data of the check dams on the main river bed in Tseng-Wen Reservoir. Further, the SDR of the watersheds for the eight reservoirs in Taiwan are examined. The result indicates that the measured sediment yield in the watersheds are similar to the estimated ones which are obtained by using the Soil Erosion Index Model, to . calculate the soil erosion and by using the SDR formula to estimate the sediment loss with the ratio of soil erosion to landslide.