A methodology for measuring the wind drag coeeficient on coastal dune vegetation: a study on seaoats (Uniloa paniculata)

Abstract

Current plant canopy wind flow models require three aerodynamic parameters to predict the effects of wind on sand transport--the plant drag coefficient, Cd, the leaf area density profile, LAD, and the turbulent eddy transfer coefficient, 6,. The LAD and Cd characterize the plant canopy and its effects on air flow and, prior to this study, data on these parameters for dune vegetation did not exist. The purpose of this study was to design and test a methodology for measuring the wind drag coefficient of coastal dune plants. The objectives were 1) to measure and record the parameters needed to calculate Cd, namely, the force, relative velocity and air temperature; 2) to measure the leaf area density of sea-oats; 3) to validate the method by measuring the quantities needed to compute the drag coefficient for a right circular data exists; and 4) to explore the Reynolds number dependence of the canopy drag coefficient. (This document has 76 pages.)