Students derive bedform phase diagrams from Middleton and Southard (1984) by plotting the original data (stolen using DataThief software from the publication) in Excel and defining bedform field boundaries. Official Full-Text Publication: A New Phase Diagram for Combined-Flow Bedforms on ResearchGate, the professional network for scientists. Under these flow conditions, ten distinctive bedform states can be recognized: no motion (NM), 2D symmetric ripples (2D SR), 3D symmetric ripples (3D SR), 3D symmetric dunes (3D SR), 3D asymmetric ripples (3D AR), 3D quasi-asymmetric ripples (3D QAR), 3D asymmetric dunes (3D AD), 3D current ripples (3D CR), 3D current dunes (3D CD), and upper-stage plane bed (USPB).
Each of these bedform stages was described, characterized and reproduced in dimensional and dimensionless phase diagrams. A complete re-evaluation of the nomenclature for combined flow bedforms is proposed, which includes their planform and the cross-sectional geometries in order to better represent the bed morphologies. Bedform phase diagrams define the boundaries between different types of bedform based on variables that describe the strength and depth of the flow and the size of the sediment forming the bed. Non-dimensional phase diagrams for current-generated bedforms. (a) A 2D section of the bedform phase diagram of Southard & Boguchwal (1990), showing 10 C-equivalent mean flow velocity against 10 C-equivalent flow depth for 10 C-equivalent mean bed sediment sizes between 0.
View Notes – Bedform20phase20diagram0 from GEOL 3430 at Colorado. GEOL 3430 Deriving Bedform Phase Diagrams Part I Due Date: Friday Feb.