Abstract
During the snow melting season some large landslides cause severe damage in heavy snowfall regions due to the increase of pore water pressure. It is important to clarify the properties of groundwater flow in these landslides during the snow melting season in order to understand the mechanism of landslide occurrence.
The long-term piezometric response of deep groundwater in the Dozangawa landslide, which is in a Tertiary area covered by pyroclastic material, was observed. A geological model for simulation was constructed using hydrogeological parameters obtained by electrical prospecting. Groundwater flow analysis by finite element method was then performed on this model and simulated groundwater flow for the snow melting season and for the rainy season.
Field observation and groundwater analysis showed that numerical simulation of groundwater flow is useful for clarifying the characteristics of groundwater flow in the pyroclastic material layer that influences the pore water pressure in a deep slip surface, and how the geomorphological characteristics of a landslide affect the piezometric response from snow melting water.
