2005-08-012024-05-18https://scholars.lib.ntu.edu.tw/handle/123456789/706863摘要：台灣位於歐亞大陸板塊與菲律賓海板塊的聚合帶上，地震與構造運動頻繁，地表上升 速率高，加上高颱風、豪雨和降雨量，地表的地形作用劇烈，塊體運動（mass movement） 經常發生，對於社會與經濟方面有許多影響。1999 的九二一大地震在台灣中部地區形 成許多大規模的新崩塌地，這些崩塌地成為地表地形作用之一，原本穩定的地區成為 亞穩定或不穩定狀態，在之後的桃芝颱風及敏督利颱風降雨的影響下，成為非常不穩 定的地區之一，崩塌地持續發育。 事實上，中部橫貫公路西段，由谷關至德基水庫段，在九二一地震之中遭受嚴重損害， 這是受到地震所產生的塊體運動而形成的邊坡不穩定現象。原本的路基在許多路段已 經完全消失，大量崩積物沿著邊坡滑落至河谷，進入大甲溪成為河川搬運物質，崩塌 地也隨著時間而演育。因此本研究希望以地形學的角度來分析中橫公路西段沿線的邊 坡崩塌現象，試圖瞭解地形因子在崩塌中所扮演的角色。 運用航照和衛星影像，說明了發生山崩的地區在地震之後的高強度降雨事件裡大量增 加。山崩影響的地區，分析懸移質沈積物資料，顯示沈積物已經穩定地隨著時間增加。 因此，從地震後沈積物量的立<br> Abstract: Taiwan located in the subduction between Euro-Asia Plate and Philippine Sea Plate. So there are a lot of earthquakes and tectonic activities, which makes the surface lifted in a very high rate. Besides, the typhoons and heavy rainfall incise the landform that makes a great deal of mass movements. This impacts our society and economy tremendously. In 1999, the big earthquake stroke central Taiwan and made many landslides. This area became quite critical since that time. And the consequent typhoon and heavy rainfall let the rebuild of the Trans-island highway almost impossible. In fact, the west part of the Trans-island highway was damaged quite seriously during the 1999 earthquake. The following typhoon and heavy rainfall made the situation even worse. The loose material that came from landslides went to the Da-cha River directly, which became the sediment of the river. The landslides evolved through time. This is the main focus of our study. We want to unveil the characteristics of landslides and the evolution of the landform in that area. landslides increased substantially in high intensity rainfall events after the main earthquake. Using analysis of suspended sediment data from downstream of the area affected by landslides, we show that sediment concentrations have steadily increased with time in the period since the event as the landslides have released the material from the hillslope. Thus, a simple model in which sediment production increases immediately after the earthquake and then steadily reduces through time appears to be over simplistic, and should be replaced by a model that incorporates complex responses to the initial and subsequent events. We will use orthorectified aerial photos and DTM to digitize the landslides in different stage. In this procedure, we will obtain the characteristics of landslides through time, which includes elevation, width, length, area, inclination, direction, slope feature and so forth. We will analyze those characteristics to build a model for the evolution of landslides.數值地形模型崩塌地演育DTMLandslides evolution