Hillslope evaluation in the vicinity of the Wolsong nuclear power plant after 12th September 2016 Gyeongju earthquake, South Korea

Abstract

Landslides result not only from the environmental background conditions of slopes but also from triggering factors, such as rainfall and earthquake. Severe landslides and debris flows are common natural disasters in South Korea since it is characterized by high rainfall and rugged topography. A secondary effect of an earthquake could be slope instability. A 5.8-magnitude (ML) earthquake, the most powerful seismic activity since the nation started measuring tremors, struck the historic city of Gyeongju, North Gyeongsan Province, at 20:32:54 KST. The Wolsong nuclear power plant is situated in the foothills of a mountainous area about 26 km SE of the earthquake epicenter. South Korea’s biggest historical earthquake raised the nuclear safety concerns. To assess regional landslide hazard under the conditions of heavy rainfall and after 5.8 ML Gyeongju earthquake, this study, a coupled hydrological model with infinite slope model was used to find the hillslope stability under the roles of rainfall and earthquake.