Susceptibility assessment of landslides under extreme-rainfall events using hydro-geotechnical model; a case study of Umyeonsan (Mt.), Korea

Abstract

Abstract. The influence of climate change on patterns has the potential to alter stability of partially saturated soil slopes. Changes in rainfall patterns have a strong influence on stability of partially saturated soil slopes, which recently have resulted in shallow landslides. In this paper, a comprehensive case study on the 2011 Umyeonsan (Mt.) landslides was highlighted. The incident involves the collapse of a soil slope and the debris flow under extreme-rainfall event, causing 16 fatalities and serious damaged to 146 housings. A fundamental study was carried out on the cause and mechanism of landslide/debris flow. An analytical method is developed for determining the failure mechanism of unsaturated soil slopes under extreme-rainfall, the effect of groundwater flow; the downward velocity of wetting front, and the upward velocity of groundwater level. Based on this, we propose the conceptual methodology of landslide design based on experimental tests and numerical analyses which consider the important mechanism of the combined effects of both groundwater flow and rainfall infiltration into the slope.

Analysis of Geotechnical-Assisted 2-D Electrical Resistivity Tomography Monitoring of Slope Instability in Residual Soil of Weathered Granitic Basement

“…Changes in water conditions and slope geometry are the main factors that induce slope instability (Tang et al, 2018) in the presence of discontinuities such as faults, fractures, and beddings which are precursors to landslide (Chalupa et al, 2018). Since, the world is experiencing heavy and extreme rainfall events because of global climate change (Kirschbaum et al, 2020), the continuous precipitation during typhoon increases slope instability around mountains which has led to severe mudflows and landslide events (Baum et al, 2010;Pradhan and Lee, 2010;Epada et al, 2012;Jeong et al, 2014;Chien et al, 2015;Hakro and Harahap, 2015;Baharuddin et al, 2016;Sidle and Bogaard, 2016;Jeong et al, 2017;Kumar and Rathee, 2017;Soto et al, 2017;Tomás et al, 2018;Kirschbaum et al, 2020). A majority of these landslides have caused a considerable loss of lives and properties (Choi and Cheung, 2013;Askarinejad et al, 2018).…”

The Effectiveness of a Wireless Sensor Network System for Landslide Monitoring

“…Rainfall-induced landslides commonly occur when the temporal saturated wetting bands are generated or the groundwater level rises due to rainfall infiltration. In other words, rainfall-induced landslides are closely related to rainfall duration, antecedent rainfall, and cumulative rainfall [7], [38]- [40]. Therefore, it is important to know the change in water content, matric suction, and surface displacement in order to predict rainfall-induced landslides.…”