The relationship between rainfall and the occurrence rate of induced landslides and vegetation recovery after Chi-Chi earthquake in Taiwan

• Main Authors: Ying-Jing Chen, 陳盈靜
• Other Authors: Chyi-Tyi Lee
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/48158145979124067031

碩士 === 國立中央大學 === 應用地質研究所 === 102 === Based on the previous studies, this study re-examined the previous data and added more data of rainfall events before 1999 and after 2010. This large data set was used to analysis the relationship between rainfall and the occurrence rate of induced landslides. We investigate the trend of landslide ratio with rainfall value and observe the rainfall threshold of landsliding. We find out the relationship between landslide ration and a rainfall factor and the combination of rainfall factors. Rainfall factors used in this study include maximum hourly rainfall, total rainfall, average rainfall intensity and maximum 3, 6, 9, 12, 24 hour rainfalls. The results of univariate regression analysis and multivariate regression analysis showed that maximum hourly rainfall, total rainfall and maximum 3, 24 hour rainfalls are fitting with the landslide ratio well and are more effective in explaining landslides. A residual after regression is defined as the difference between observed value and predicted value for the landslide ratio. We plot the residuals against the time and observe the change of residuals with time. The results showed that the areas affected by Chi-Chi earthquake (central Taiwan) have gradually restored in the last decade.