fluvial_processes_notes

fluvial_processes_notes - 1 Surface Processes and Landforms...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Surface Processes and Landforms (12.163/12.463) Fall 02 -- K. Whipple 1 FACTORS INFLUENCING HYDRAULIC ROUGHNESS Bed material size (D 50 , D 84 , k s , z o , n g ); Relative roughness (h/D 50 ); Presence of sediment transport (momentum extraction); Bedforms and barforms; Vegetation; Obstructions (tree stumps, logs, boulders, bedrock outcrops, ect); Variations in channel width and depth; Channel curvature (sinuosity) METHODS FOR ESTIMATING ROUGHNESS PARAMETERS "Roughness" is represented in various ways in familiar flow velocity equations. We will consider: Chezy±s equation, Manning's equation, the Darcy-Weisbach equation, and a generalized D-W equation (all for average velocity), and the "Law of the Wall" equation for the velocity profile or a turbulent flow near a boundary (logarithmic). Variables Used: S : Water surface slope (= bed slope for steady uniform flow) [m/m] R h : Hydraulic radius (R h = A/P = flow depth for infinitely wide channel) [m] A : Cross-sectional area [m 2 ] P : Wetted perimeter [m] Q : Water Discharge [m 3 /s] u : Cross-sectionally averaged velocity [m/s] z : cartesian coordinate (perpendicular to bed) [m] h : flow depth (perpendicular to bed) [m] W b : basal shear stress [Pa] k : von Karman±s constant = 0.40 C : Chezy roughness coefficient [m 1/2
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 03/12/2012 for the course GLG 362 taught by Professor Staff during the Fall '11 term at ASU.

Page1 / 16

fluvial_processes_notes - 1 Surface Processes and Landforms...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online