運用數值地形模型初探草嶺山崩地區百年來地表變遷

Centennial geomorphologic change analysis around Tsaoling landslide area based on multi-sourced digital terrain models

李虹瑾(Hung-Chin Li)

指導教授 ： 張國楨

國立臺北科技大學/工程學院/土木與防災研究所/碩士(2011年)

https://doi.org/10.6841/NTUT.2011.00297

摘要

草嶺地區位處於西部麓山帶內，地形變化大，為一大型順向坡地形。草嶺地區山崩活動已有百餘年歷史記錄；在豪雨、地震等因素催生下，近百多年來已有五次記錄，成為一探討同一地點、多次山崩的極佳例子。1999年集集地震之後，已有許多學者投入心力於草嶺山崩的研究工作上，但是受限資料之取得，對於1979年以前山崩資料歷史，較少著墨，故尚缺乏詳細記錄。
本研究利用日治時期地形圖、美軍多色地形圖等高線地形資料，利用數化等高線法來建置二十世紀初期草嶺地區之數值地形模型，並配合地理資訊系統來整合、套疊各時期歷史地形圖及數值地形模型，以做為地形地貌分析之基本資料。在本研究中，也配合農林航空測量所之傳統影像及數位化高精度航空影像，利用航空攝影測量技術製作數值地形模型，搭配即時動態全球定位系統，進行現地地面控制點資料點的量測，並相互校正，建置最新的數值地形模型。最後，套疊不同時期所建置的數值地形模型，經由各時期高程平差與對比，在不同時期地形圖所涵蓋之地區，獲得歷史性山崩之地形資訊，試圖比對及推估草嶺地區之地形變遷。
本研究成果建置了數個不同時期2公尺解析度之DTM。從建置所得的DTM與相對應之正射影像，來探討許多地形變化如：山崩崩塌量體的估算、堆積區範圍及外貌，河道侵蝕及河道變遷，各時期草嶺潭的存歿等。透過歷史資料重建草嶺地區不同時期的地表資訊，進而恢復歷年來草嶺地區受到山崩影響之地形、地貌，並探討其改變的原因與環境的影響。

關鍵字

數值地形模型 ； 日治時期地形圖 ； 草嶺山崩 ； 集集地震

並列摘要

Tsaoling area is located on the foothill in western Taiwan. The topographic change is large and the area is on a large dip slope. The landslide activity in Tsaoling area was first recorded more than a hundred years ago. As accelerated by heavy rainfall and earthquakes, there had been five landslide activities recorded for the last hundred years. Thus, Tsaoling area is the best example when discussing the occurrence of many landslides in the same area. After the ChiChi earthquake in 1999, there have been many experts who devoted themselves in investigating the landslides in Tsaoling. However, as the access to the data is limited, not many people wrote about the landslides before the year of 1979. Therefore, there are lacked detailed records.
In the research, contour topographic data such as the topographic map from the Japanese and the U.S. army topographic map and digital contour mapping were used to construct digital terrain models of the Tsaoling area in early twenty century. Moreover, with correspondence to the Geographic Information System, the topography maps and digital terrain maps for different periods of time were combined and overlapped to produce the basic information for terrain and geomorphology analyses.

In the research, the traditional images and high-precision digital aerial images from the Aerial Survey Office and the aerophotogrammetry techniques were used to construct digital terrain models. Along with real-time kinematic GPS, the ground control points and data points of the location were measured. The points calibrated each other to construct the latest digital terrain models. Finally, the digital terrain models for different periods of time were overlapped. The terrain information of historical landslides was obtained for the area covered by the topographic maps for different periods of time through the comparisons and contrasts of height adjustments for different periods of time.
In terms of the research results, 2-meter resolution digital terrain models for different periods of time were constructed. From the digital terrain models constructed and the corresponding ortho-images, the topographic changes discussed included: The estimation of the landslide volume; The area and appearance of the accumulation area; Channel erosion and channel shifting; The remaining of Tsaoling lake during different periods of time. The surface information of Tsaoling area during different periods of time were constructed using historical data in order to reshow the terrain and geomorphology of the Tsaoling area that had been affected by landslides over the years. The causes for the changes and the impacts of the environment were discussed.

並列關鍵字

Digital terrain model ； Japanese topographic map ； Tsaoling landslide ； ChiChi earthquake

參考文獻

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