1. Process Geomorphology

2. 10/13 Objectives Learning Objective: Understand the concepts of driving and resisting forces, and constitutive equations in geomorphologic processes. – Example of the use of constitutive equations to model flow processes – Example of the use of continuity and motion equations to model slope form. – Comments on projects – Comments on midterm.

3. Debris Flow Constitutive Equation Constitutive equation must model observed behavior – See table of mass movement types Debris flows require – Critical shear before motion (yield strength) – Following failure, strain rate is linear with stress Combines elements of – Ideal fluid (Newtonian Fluid) – Ideal plastic Bingham plastic – See notes on board

4. Modeling hillslope form Hillslopes may be dominated by relatively frequent diffusive erosion or less frequent mass failure – These two situations tend to coincide to where stream incision rates are low and high, respectively – Let’s assume erosion by diffusive processes alone

5. Diffusion Equation 1D continuity equation for sediment in a control volume Motion equation for sediment transport – On board