Stream Channel Formation, Hydrology and Maintenance

Stream Channel Morphology & Hydrology

I. Channel Morphology A. Variables 1. W = width 2. D = depth 3. S = slope 4. A = cross sectional area 5. R = hydraulic radius 6. P = wetted perimeter B. Flow Q = AV C. Uniform flow Q = A1V1 = A2V2 D. Laminar vs. turbulent flow 1. viscous vs. gravitational forces 2. Reynolds number NR = ρ [VR/µ] E. Turbulent flow 1. Streaming flow vs. shooting flow 2. Froude number F = [V/ √gD] F. Effects of the channel bottom 1. Chezy formula V = [C √RS] where C is a constant 2. Manning’s number V = 1.49/n * R2/3 * S1/2 Where n is Manning’s number – a measure of bottom roughness

II. Energy and Work A. Energy 1. Potential energy Ep = Wz 2. Kinetic energy Ek = [MV2/ 2]

III. Transport and load A. Dissolved load B. Suspended load C. Bed load E. Work of the stream 1. competency 2. capacity D. dynamics of transport

III. Valley Morphology A. The long profile B. Drainage basin metrics C. Stream order D. Other drainage features 1. terraces 2. meanders E. Stream adjustment F. The graded profile