The Effect of Chaotic Dynamical Behavior of Rainfall on Landslides

• Main Authors: Ni-Yen Wu, 吳妮晏
• Other Authors: 楊長義
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/62067409730425296825

碩士 === 淡江大學 === 土木工程學系碩士班 === 93 === This research is doing on the relationship between raining behaviors and landslides by using the scalar and dynamic properties: (1)depicting the differences of the three types of raining which brought up by Hiroshi Ikeya by fractal dimension, and using some conditions as the amount of of rainfall before landslide and days of raining to attribute the likelihood of occurrence of failure；(2)indicating the fractal properties of rainfall on the time series by box dimension of dynamic raining behavior of Typhoon Mindulle，and show the complicacy of raining by this result, on the same time, using the raining chaos dynamical behavior before landslide to explain the precise respect of forcasting time by the landslide. Finally, we consider by parts of static or dynamic reasons and the landslide susceptibility union effect in Nantou，and reconsider the dangerous of landslide in Nantou. The following are the main results:(1) Hiroshi Ikeya defined the first kind of raining condition similar to the gap graded of the soil grain-size distribution curve, but the second and the third condition were similar to the well graded. That proved “Db” could be used to describe the raining condition.(2) During 91 years to 93 years,The average of landslide impossibility Lf are situated between 26.67%~50%,in various counties of Taiwan indicated that Taiwan partial counties are usually easy to trigger the landslide condition; Among them,The Lf in Nantou County is situated between 40%~60%, The impossibility of triggers thelandslide is higher than other counties.(3) In Nantou area, it needs four or five phase space to discribe the rainfall dynamic characteristic during Typhoon Mindulle,but for long-term rainfall just needs two or three, therefore the behavior of rainfall dynamic characteristic during Typhoon Mindulle is more complicated then usual obviously.(4) Accumulation rainfall and landslides are irrelevant.(5)Energy & Resources Laboratories considered box dimension Db(T), the short-term rainfall dynamic factor, to assess landslide susceptibility of Hsitou. Survey the avalanche data during Typhoon Mindulle, it appear that Likelihood of failure occurrence of each avalanche point is higher than original landslide susceptibility, indicating that assessment of landslide subsumed rainfall incentive tally with real condition. In addition, it’s more tallying with real condition considering Db(T) than that consider Lf, long-term rainfall incentive.