A probability based early warning system for rain-induced landslides - A case study of Taipei City
Journal
Proceedings of the 17th International Conference on Soil Mechanics and Geotechnical Engineering: The Academia and Practice of Geotechnical Engineering
Journal Volume
3
Pages
2605-2608
Date Issued
2009
Author(s)
Abstract
On September 15, 2001, Typhoon Nari struck Taiwan with heavy rainfall inducing more than 400 landslides in Taipei City. In order to reduce the landslide hazards, the early warning system is much needed. To develop the warning criteria, the landslide events caused by Typhoon Nari along with events occurred in 2004 were used. Field investigations and documentation of the occurring time of each event were conducted carefully to validate the data. By cross-comparisons of the rainfall records from different rain gauge stations, Taipei City was divided into 3 subzones taking into account the geomorphological condition, distribution of the geological formations, and characteristics of rainfall pattern. Methods for determining the representative and effective rainfall parameters at the landslide sites were determined based on the rainfall records of the rain gauge stations. The probability-based early warning criteria were established using the rainfall intensity and effective cumulative rainfall at the occurring time of the events as the key parameters. The criteria were verified by simulating the landslide event induced by typhoon Crosa on October 7, 2007, and proved to be effective and feasible with satisfactory results. The resulting early warning system for landslide in Taipei City can be used to support decision making during the emergency response and for hazard mitigation of rainfall induced landslide.
Type
conference paper