2006-08-012024-05-17https://scholars.lib.ntu.edu.tw/handle/123456789/690387摘要：本研究將延續過去中橫山崩的研究計畫，持續蒐集大甲溪流域近幾年颱風前後的 影像資料，包括桃芝颱風及敏督利颱風等航空照片，利用正射影像來觀察及分析山崩 發生的機制及原因，以及在不同事件下對集水區地形發育的影響。從初步的研究發現 由地震所觸發的山崩事件是在稜線上產生的，這種現象有一種可能是受到地震波所控 制，導致在邊坡上產生共振效應，增加在山頂的地表加速度，因此觸發山崩的產生。 然而從地震後的航照來看，隨後的降雨事件更帶來更大的山崩災害。 本研究發現在地震後河川搬運沈積物的效率有明顯提升，在集集大地震前原本大 甲溪流域是屬於沈積物供應限制的狀況，集集大地震增加沈積物的供應量，也將原本 的沈積物平衡改變，轉移為搬運限制。 因此這些水文資料的改變除了受到崩塌地的影響，似乎與當地颱風降雨的變化有 關，本研究將持續蒐集大甲溪當地的水文及氣候資料並進行分析。第三年度重點則在 野外調查驗證過去航照衛星照片的成果，同時檢討大甲溪河川輸沙來源及可能的演 育。預期研究成果將可瞭解大甲溪流域在不同時間、不同事件下的地形變化，並從觀 察分析的成果進一步說明災害發生的原因及特性以及氣候及水<br> Abstract: In this research, we would like to continue the landslide study in Da-cha drainage basin. By using aerial photos and ortho-rectification technique, this study can reconstruct and analyze the characteristics of landslides in study area, including those photos taken after typhoon Toraji of 2001 and Mindole of 2004. The study will focus on the types and mechanics of landslides from the ortho-rectified image. There we can understand the evolution of landform in this area. In previous study, we found that earthquake could be a very strong agent in landform evolution. The 1999 earthquake triggered quite a lot of landslides near ridges for the sake of strain accumulation. And the following heavy rainfalls made the situation even worse. We also found that river transportation efficiency apparently increases in previous study. The fluvial system of Da-cha River was transformed from weathering limit to transportation limit for the sake of debris whic h was made by 1999 earthquake. From the previous study, we would like to focus on the linkage between landform change, landslides and sediment transportation, by using sediment concentration data, landslides data (both aerial photos and FSII image). We will reconstruct detail landslides history to analyze the relationship between landslide hazards, weather and hydrological events. This result will be used in policy making or regional development purposes.數值地形模型崩塌地演育大甲溪航照判讀DTMLandslide evolutionDa-chaAerial photo interpretation.