HR: 0830h
AN: H51D-1093    [PDF]
TI: Effects of Drainage basin property and geological dip - strike angle on Landslide
AU: * Kawabata, D
EM: d-kawabata@aist.go.jp
AB: The recent spread of GIS and high-precision DEM has been making rapid and extensive topographical measurements feasible. GIS is helpful tool to analysis of landslide probability and make landslide hazard map. We have investigated that the altitude-slope relationship for each geological unit (e.g. sandstone-dominant, mudstone-dominant, sandstone-mudstone alternation) in the Southern Japanese Alps. This result shows that terrains underlain by some specific rocks, however, are highly susceptible to landslides and thus have markedly reduced slope angles than other terrains with similar altitudes. It is another result of our investigation that the characteristics slope failures like toppling is difference from landslides. In our study, it is not clear of the relationship of dip angle of the geology and aspect in landslide area. In addition to this subject, the problem which we consider next is what the other factor decides landslide distribution. Relationship drainage basin and landslide is focused in this study. The results of morphometric measurement, over 70% landslides are on the geological boundary. The slope angle of landslide area is 10-15% lower than dip angle of geological unit. The dip angle direction of geological unit shows similar trend of aspect of landslide. Many Landslides are on the low drainage density and high slope angle area. Drainage density is low and it has large area in geological unit include many landslides. These results show that landslides are easy to cause in a place like similar dip direction and dip angle of the geological unit. It is likely that landslides tend to cause in the place where material is different. Large drainage basin and high slope angle effects on landslide distribution.
DE: 1824 Geomorphology (1625)
DE: 9320 Asia
SC: Hydrology [H]
MN: 2003 Fall Meeting