Abstract
When heavy rains fall, the landslides frequently occur in valley heads. These reasons are that underground water concentrates easily and piping occurs because of groundwater discharge. This study is the basis to predict a landslide generation in valley heads. The prediction of a landslide in valley heads needs the 3D subsurface flow simulation. The purpose of this study is, first, to analyze subsurface flow in 3D considering land form, soil layers and pipe flow, and second, to evaluate the landslide potential in valley heads. We targeted the landslide that actually occurred in Fukushima in August, 1998. The result is that our model can almost accurately predict the time of landslide and piping generation, and there is a possibility that as the history of heavy rain continues, piping grows and landslide potential increases in valley heads.
