Slope debris flows in the Wenchuan Earthquake area |
| |
| Authors: | Yanfu Li Zhaoyin Wang Wenjing Shi Xuzhao Wang |
| |
| Institution: | (1) State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, Chengdu University of Technology, 1# Erxianqiao dongsanlu, 610059 Chengdu, People’s Republic of China |
| |
| Abstract: | Avalanches and landslides, induced by the Wenchuan Earthquake on May 12, 2008, resulted in a lot of disaggregated, solid material
on slopes that could be readily mobilized as source material for debris flows. Rainstorms triggered numerous slope debris
flows with great damage to highways and rivers over the subsequent two years. Slope debris flows (as opposed to channelized
debris flows) are defined as phenomena in which high-concentration mixtures of debris and water flow down slopes for short
distances to highways and river banks. Based on field investigations and measurements of 19 slope debris flows, their main
characteristics and potential mitigation strategies were studied. High rainfall intensity is the main triggering factor. Critical
rainfall intensities for simultaneous occurrence of single, several and numerous slope debris flow events were 20 mm/day,
30mm/day, and 90 mm/day, respectively. Field investigations also revealed that slope debris flows consist of high concentrations
of cobbles, boulders and gravel. They are two-phase debris flows. The liquid phase plays the role of lubrication instead of
transporting medium. Solid particles collide with each other and consume a lot of energy. The velocities of slope debris flows
are very low, and their transport distances are only several tens of meters. Slope debris flows may be controlled by construction
of drainage systems and by reforestation. |
| |
| Keywords: | Slope debris flow rainfall intensity Wenchuan Earthquake landslide avalanche |
| 本文献已被 CNKI SpringerLink 等数据库收录！ |
|
