Japan Geoscience Union Meeting 2019

Presentation information

[J] Oral

H (Human Geosciences ) » H-GM Geomorphology

[H-GM04] Geomorphology

Wed. May 29, 2019 9:00 AM - 10:30 AM 101 (1F)

convener:Tsuyoshi Hattanji(Faculty of Life and Environmental Sciences, University of Tsukuba), Masayuki Seto(Fukushima Future Center for Regional Revitalization, Fukushima University), Chairperson:Tsuyoshi Hattanji

10:00 AM - 10:15 AM

[HGM04-05] Characterization of the vertical unsaturated flow for an integrated prediction of the storm runoff response and landslide initiation on a hillslope

*Makoto Tani1, Yuki Matsushi2, Takahiro Sayama2, Nagahiro Kojima3 (1.University of Human Environments, 2.Disaster Prevention Research Institute, Kyoto University, 3.Lake Biwa Environmental Research Institute )

Keywords:Integrated prediction of storm runoff and landslide initiation , Hillslope hydrology, Vertical unsaturated flow, Soil-layer evolution

Studies on hillslope hydrology have demonstrated storm runoff responses are generated mainly through subsurface flow instead of overland flow, and studies on erosion control have empirically revealed landslides usually occur at the time of intense rainfall after a large cumulative rainfall. based on these findings, we have to explain with consistency that the flow generation mechanism for large magnitude storms on hillslope can produce both hydrograph responses below a threshold condition of rainfall and a landslide initiation above the threshold. Recent observational studies have shown vertical unsaturated flow within a hillslope soil layer may dominantly control the responses of ephemeral groundwater table to storm rainfall through the pressure-head propagation and that the responses are rather transmitted to the stream runoff with little modification. The present study discusses the reason why the vertical unsaturated flow can produce the runoff responses during large magnitude storms and provides a perspective on an integrative prediction of the storm runoff response and landslide initiation