崩坍對河道沖淤之影響研究

Study on the Effect of Landslides to Scour-and-Fill of River Channel

黃宏斌(Hung-Pin Huang) ； 廖翊鈞(Yi-Jiun Liao)

《中華水土保持學報》 22卷1期 (1991/05) Pp. 69-83

https://doi.org/10.29417/JCSWC.199105_22(1).0007

摘要

目前國內雖然已有許多關於河道沖淤和表土沖蝕之研究，惟對於崩坍地之土砂産量對集水區輸砂量之影響探討仍嫌不足。事實上，因地形，地質，氣候等因素之影響下，崩坍地普遍存在於各主要集水區；而且，其崩坍土方量常超過河道自身沖淤者。本研究嘗試探討崩坍土方量與輸砂量模式之相互關係，配合定量流之河道輸砂演算，藉以預測崩坍產出量對於河道所造成之影響。研究步驟為：1.在未加入崩坍土方量下，進行輸砂演算。並且分析比較不同模式演算結果之差異。2.加入崩坍土方量，重覆前項之分析與比較。研究結果如下：1.崩坍土方量除增加河道輸砂量外，對地形、地貌也有相當程度之影響。2.不同公式具有不同之特性與適用範圍。在地形變化劇烈之處，不同公式之演算結果會有較大之差異。3.若以流量為橫軸，輸砂量為縱軸時，淤積段有順時針，沖刷段則有逆時針之迴路現象。若斷面處於不沖，不淤之狀態時，迴路便退化成一直線。

關鍵字

崩坍 ； 輸砂量

並列摘要

At the present, there have been many paper concerned with sediment transport and surface erosion, but very few with the effects of landslides to watershed., In fact, the phenomena of landslides exist in most of watersheds and the sediment discharge from landslides usually exceeds those from river itself. This study tried to explore a relationship between landslides and sediment transport models. Associated with steady flow condition, the calculation of sediment transport was conducted to predict the effects of sediment discharge from landslides to river channel. Approaches in this study are: 1. Calculated the sediment discharge by each model without landslides, then analyzed and compared differences between them. 2. Added sediment discharge from landslides and repeated the same procedure of analysis and comparison. The conclusions were: 1. Landslides did not only increase sediment discharge but also affect the geography and morphology of watershed. 2. Each model had its own characteristics and range of application. In rapid varied area, different models would show a large discrepancy of their results. 3. In case of setting flow discharge as abscissa and sediment discharge longitude, deposit section showed clockwise while scour section counterclockwise loop. For equilibrium section, loop would change to line.

並列關鍵字

landslide ； sediment discharge