潛在大規模崩塌之降雨、溪流電導度與地表位移之關聯性研究－以竹林地區為例

Study on Correlation between Rainfall, Electrical Conductivity and Surface Displacement of Potential Large-scale Landslide-Case Study in Zhulin Area

陳懿靜(Yi-Jing Chen) ； 蔡元融(Yuan-Jung Tsai) ； 謝正倫(Chjeng-Lun Shieh)

《中華防災學刊》 12卷1期 (2020/03) Pp. 35-42

摘要

大規模崩塌的監測及預警方法開發為目前政府坡地防減災工作的重要議題之一。本研究選定高雄六龜竹林潛在大規模崩塌區，透過降雨、溪流電導度與地表位移等因子之關聯性進行探討，評估溪流電導度做為潛在大規模崩塌活動性變化指標的可行性。在空間分布上，溪流電導度會隨著與潛在大規模崩塌區坡趾距離變化，當距離越近時，電導度越高，而隨著距離之增加而降低。而在時間分布上，竹林地區在降雨事件過後不論是地表變位或是電導度均有有相似變化趨勢及一定相關性，尤其是連續降雨後都會出現明顯抬升，其中電導度與7天累積降雨影響相關性較高，而地表位移量則與尖峰雨量有約15天之落差，因此透過電導度之連續觀測，可以用來掌握潛勢區之活動性變化情形。因此對潛在大規模崩塌區的溪流進行電導度量測是有效的，電導度之空間變化可以用來找到潛勢區內活動性較高之區域，而從時間之變化可以評估區域內水文系統之變化及地表位移狀況，間接判斷潛在大規模崩塌區之活動性變化。

關鍵字

大規模崩塌 ； 溪流電導度 ； 地表位移 ； 降雨

並列摘要

The development of early warning system for large-scale landslide (LSL) is one of the most important issues for slope area risk prevention and reduction in Taiwan. In this paper, correlation between stream conductivity, rainfall and surface displacement in Zhulin potential LSL is discussed. The purpose of this research is to estimate the feasibility of using stream conductivity as one of the indicator for large-scale landslide activity. In space, stream conductivity gets higher closer to the potential LSL which could be used to find out more active parts of the potential LSL. In time, there is a similar trend and certain correlation between the surface displacement and the conductivity after the rainfall event, especially after continuous rainfall. This finding could applied to assess the changes of hydrological system and surface displacement. Based on the research results, the activity variation of potential LSL could be indirectly determined.

並列關鍵字

Large-scale Landslide ； Electrical Conductivity ； Surface Displacement ； Rainfall