極端降雨引致坡地災害對新店溪流域之衝擊與影響

極端降雨常造成嚴重的災害衝擊和損失，為能夠在災害發生初期，透過有限資訊的掌握來瞭解衝擊較嚴重的區位及程度，本研究以2015年蘇迪勒颱風在新店溪流域造成的土砂災害為例，透過災後崩塌判釋、歷史圖資、現地調查等方法，評估本次颱風事件所造成的衝擊。結果顯示主要災害發生在南勢溪及平廣溪，其中南勢溪流域內之崩塌衝擊位於道路及河谷沿線，平廣溪集水區較大衝擊來自於崩塌及土石流，其中土石流和崩塌所造成的土砂量比約為1：2。為在災後初步瞭解土砂量對下游的影響，進一步以經驗公式推算泥砂濃度。結果顯示短延時、強降雨易造成小集水區瞬時泥砂濃度極高的現象，後續對下游河川將造成很大的影響。

關鍵字

蘇迪勒颱風；崩塌；土石流；泥砂濃度；災後快速推估技術

並列摘要

Extreme rainfall brings serious disaster impacts and losses. This study aims to clarify the zonation and levels of areas with high sediment disaster impacts in the initial period during disaster event in terms of limited information. This study carried out disaster impact assessment during Typhoon Soudelor in 2015, employing with landslide classification, historical data, and field investigation. The result shows that the main disasters occurred in Nanshi and Pingkong stream catchments. In Nanshi stream catchment, landslide disaster impacts distributed along road and river path, and the larger disaster impact in Pingkong stream catchment were from landslide and debris flow with sediment volume ratio about 1:2. Sediment concentration empirical equation was used for clarifying initial sediment impact to the downstream area. The result represents that the rainfall with short duration and high intensity easily causes extremely high sediment concentration in small watersheds and then results in large impacts to the downstream area.

並列關鍵字

Typhoon Soudelor ； Landslide ； Debris flow ； Sediment concentration ； post-disaster rapid assessment technology

參考文獻

中央氣象局，2015，〈颱風資料庫〉，2016 年10 月8 日，摘錄自http://watch.ncdr.nat.gov.tw/raints.aspx、http://rdc28.cwb.gov.tw/TDB/ntdb/pageControl/typhoon?year=2015&num=201513&name=SOUDELOR&from_warning=true