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.

Hydrostatic Pressure curveFactor of Safety curve


Figure 7. (A) Pressure head–depth curves during the first 16 hrs of the storm by Eqn. 5a for a soil cohesion of 2 KPa, diffusivity of 10-3 m/s, k/I =1, water table depth at 1 m. The dash-dot line is the initial hydrostatic pressure curve and the dotted line is the hydrostatic pressure curve when the soil is completely saturated. (B) Factor of safety-depth curves calculated from Eqn. 7 for the pressure head response in (A). Color curves denote 4h (green); 8h (red); 12h (pink); 10 h (black); and 16h or 4d (blue) as labeled. .