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

Figure 1. Diagram illustrating the parameters involved in the factor of safety equation (Eqns. 1 and 4). Tree root-soil system is located above the failure plane (D denotes depth to failure plane) where q_o is tree surcharge, C_r , C_s are root and soil cohesion, and a is slope angle. (From Hammond et al., 1992)