位於西部麓山帶的草嶺地區,海拔高度介於400~1400公尺。區域內最高的草嶺山,因有南側的清水溪及北側的清水溪支流石鰻坑溪的侵蝕下切,而形成高聳獨立的順向坡地形。九二一集集地震時,強烈的地動引發了草嶺地區大規模的山崩。草嶺山山崩塊體沿著地層層面向西南滑動,部分塊體飛越清水溪河谷,堆積於對岸舊有之崩積物小丘-倒交山上方。大量的崩塌土方堆積在清水溪河谷內,堵塞河道而產生一堰塞湖-新草嶺潭。 本研究應用遙測軟體,分析地震前後各個不同時期所拍攝的航空照片,並建置地震前後2公尺數個不同時期高解析度數值地形模型。並根據所建置之數值地形模型,來分析草嶺地區之地質、地貌特徵,並研判可能之活動構造及山崩崩塌量體的估算。 為防範新草嶺潭潭水高漲可能引發潰堤,造成二次災害,震後同年年底即進行河道疏導的工作,此人為的人工處理措施亦對清水溪之後續河系發育造成不同程度的影響。利用不同時期之航空照片所建立之不同時期的數值地形模型,不同時期河床的高程差異,亦可反應了清水溪及山崩滑移面的不同區域及不同年份上的坡面、河床等區域的侵蝕及堆積速率的變化及影響。本研究根據上述各點進行探討,最後提出山崩區內,地表侵蝕、堆積作用的作用模式及速率。
Tsaoling area located in the of the Western Foothills belt with an altitude between 400 to 1,400 meters. Due to high erosion rate by Ching-Shui River on the southern side and Shi-Man-Keng River on the northern side, the highest hilltop in the region: Tsaoling Mountain, forming a large dip-slope. During the 921 earthquake, violent earth shaking caused a large scale of landslides. Tsaoling landslides followed the slope moving southwest ward. Many boulders were thrown across Ching-Shui valley, accumulated around the banks, and blocked the river to form a dammed lake, now known as-New Tsaoling Lake. This research utilizes the Remote Sensing software to analyze different aerial photographs taken at different periods, before, during and after the earth quake. The goal is to reconstruct a numbers of different periods of high resolution Digital Terrain Models. Using the models, we are able to analyze the geology and geomorphological evolution of the Tsaoling area. Furthermore, we will be able to estimate the possible geological structure and the volume of landslide. Soon after the earthquake, in order to reduce the subsequent secondary hazards, many efforts have been done, e.g. draining, evacuation le accumulated water body, etc. This human intervention caused different degrees of impact to the development of the river system. The digital terrain models will help to study the riverbed evolution during different periods. In addition, the erosion and accumulation rates affecting the changes to the river system can be evaluated accordingly. This research tries to estimate the rate of land erosion and accumulation, and the morphological impacts in this area.
為了持續優化網站功能與使用者體驗,本網站將Cookies分析技術用於網站營運、分析和個人化服務之目的。
若您繼續瀏覽本網站,即表示您同意本網站使用Cookies。