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標題: 考慮時間空間尺度之坡地災害及受災潛勢研究-子計畫:極端氣候狀態下之坡地災害行為之探討
Study on Slopeland Disaster under Extreme Climate
作者: 蘇苗彬
關鍵字: 土木水利工程類, 防災工程
摘要: 地質脆弱、坡陡流急、地震頻繁、颱風雨強且集中等因素造成台灣多坡地災害,尤其以地震與颱風所造成的災害損失最為巨大。全球氣候變遷雖仍非定論,但全球各國對氣候異常事件的報導明顯增加則是事實,台灣也不例外,極端氣候事件出現的頻率有增多的趨勢,而其所造成的災害規模也明顯擴大,因此更不可忽略其所可能帶來的衝擊。過去對極端氣候事件對坡地災害的影響之研究較少,其破壞機制尚屬未知,故站在防災、減災的立場來看,此項研究有其必要性與迫切性。崩塌、地滑與土石流為最主要的坡地災害,其在極端氣候狀況下(即強大集中的降雨, 或極大累積雨量),水在觸發災害上扮演著極重要的角色,地面上的地表逕流、土層中的滲流,與地下水三者交互作用,其關係隨著時間不斷地改變,而相對的抗滑的強度也隨著時間而變,對其作用機制的瞭解非常有必要, 因為只有瞭解此機制才能研擬對策,而設計出一勞永逸的防災治理方法,本計晝的目的即在探討此機制。本研究擬針對特定災區與潛在災區進行完整的資料收集,並設置監測系統進行監測,然後針對所收集資料進行整理與各項分析, 將應用統計方法求得摘要統計量,並以假設檢定的技術來確立或否證一些不確定的猜測,以相關分析來瞭解變數之間相關性的強弱,以迴歸分析來建立統計模式,並進行模有效性的驗證。另一方面,由基礎理論來推導出一物理模式,並將其轉換為數學模式,通常是一組偏微分方程式及一組初始與邊界條件,然後以解析方法來求解,若無法求出解析解則改以數值方法求解。再應用現成的分析工具進行數值模擬,與所發展模式做比較,進而做必要的修正,如此即可瞭解邊坡破壞的機制。
Taiwan suffers from many slope land disasters due to its weak geological properties,steep slope lands, abundant earthquakes and concentrated heavy typhoon rains. The losscaused by earthquakes and typhoons are the most significant among all losses. The globalclimate change is still non-conclusive. However, the related reports, from countriesaround the world, are more frequent than before. This is also true in Taiwan. Thefrequency of extreme weather events are increasing. The scale of the related disasters islarger. Therefore, we must not overlook the potential impact. There are few studies on theimpact caused by extreme climate events in the past. The failure mechanism is stillunknown yet. Hence, there is an urgent need of such a study from the point of view ofdisaster prevention and reduction.Landslides and debris flows are the major disasters in slop land. Under extremeweather conditions (i.e., concentrated heavy rains or high cumulative rains), water playsan extremely important role in triggering disasters. Surface runoff, seepage in soil layer,and groundwater are all time-dependent variables. Their interaction is very complicated.The strength of sliding resistance also depends on time. Understanding the failuremechanism is very important. It is very useful to know the mechanism fully to developthe best strategy for disaster prevention and reduction. The once and for all design for thedisaster control can thus be devised as well. Understanding the mechanism is the purposeof this study.The first step of this study is collect data as complete as possible from selecteddisaster areas as well as potential disaster areas. Proper monitoring system will beinstalled. The collected data are organized into useful forms for subsequent analysis.Various analyses are performed. Statistical methods are used to summary the data.Reasonable conjectures are posed and transformed into hypotheses. Then, the hypothesistesting technique is applied to draw the corresponding statistical conclusions (i.e., rejector not reject the hypothesis). The strength of correlation between any two variables isobtained using correlation analysis. The relationship among variables is modeled usingregression analysis. The validity of the model is verified using available observed data.On the other hand, a physical model is derived based on some fundamental principles.Then, it is transformed to a mathematical model which in general is a set of partialdifferential equations and initial and boundary conditions. Analytical methods are used tosolve the problem. If no analytical solution is available, then numerical methods will beused instead. Analysis tools are also used to conduct numerical simulations and comparewith results obtained by the developed model. Corrections and modifications are made ifinconsistency is found. Thus, the mechanism can be well understood.
其他識別: NSC99-2625-M005-007-MY3
Appears in Collections:土木工程學系所



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