U. S. Geological Survey

 A Comparative Analysis of Hazard Models for Predicting Debris Flows in Madison County, Virginia


By


Meghan M. Morrissey, Gerald F. Wieczorek, and Benjamin A. Morgan
Open-File Report 01-0067


2001

Click on an image for a 2X view.

Soil Cohesion curvesWater Table Depth curvesFactor of Safety curves


Figure 6.  Factor of safety-depth curves demonstrating the effects of (A) soil cohesion, (B) initial water table depth, and (C) hydraulic diffusivity after 4 hr (green lines) and 16 hr (blue lines) of rain infiltration.  Unless otherwise noted, the initial water table is 1 m, soil cohesion is 2 KPa, and hydraulic diffusivity is 10-4 m/s for these calculations. Color curves denote 4h (green); 8h (red); 12h (pink); 16h (blue) as labeled.