太麻里溪集水區降雨崩塌對河道淤砂之影響

The Influence of Rainfall on Landslide and Sediment Control Stratagem in Taimali Stream Watershed

許中立(Chung-Li Hsu) ； 鍾斌全(Pin-Chuan Chung) ； 戴欣怡(Shin-Yi Dai)

《坡地防災學報》 7卷1期 (2008/03) Pp. 1-21

https://doi.org/10.29995/JSHR.200803.0001

摘要

太麻里溪集水區之中上游地質脆弱，受豪大雨影響易造成集水區內大量崩塌發生，而崩塌之土砂受洪流挾帶堆積於河道底床，抬高河床縮小通水斷面致洪流溢岸，改變主流流向沖擊凹岸堤防致其基礎淘刷破壞，皆是致災的原因。崩塌地的產砂量與河道淤砂量皆與降雨量有密切的關係，利用航測圖資、影像及實地測量資料，可有效推求降雨與崩塌地產砂量及河道淤砂量之關係式。又根據分析結果本區年淤砂高度為32公分，約9萬立方公尺，此可作為未來河川治理方案之參考。

關鍵字

降雨 ； 洪水 ； 崩塌 ； 輸砂量

並列摘要

The weak and broken geology in the middle and upper of Taimali stream watershed caused many landslides accused and sediment transport with the stream flow deposit on the stream bed. The elevation of stream bed rose after the rainfall and landslide sediment deposit. Thus, shrinking the runoff section caused the problem of peak runoff overflow, will change mainstream flows to the impact concave shore embankment to send the foundation to wash and brush the destruction. The amount of landslides sediment transport and deposit on the stream bed was closely related to the rainfall. In this research, using photography image and field survey data can effectively estate the amount related equation of rainfall, landslides sediment and deposit. According to the analysis result, this watershed annual deposit high was 32 cm and about 90000 m^3 sediment deposit on stream bed, the watershed sediment produce still on the controllable range at present, so propose that adopting the treatment of built the control work to block all sediment can get the greatest benefit.

並列關鍵字

Rainfall ； Flood ； Landslide ； Amount of sediment