Influence of vegetation cover on sand transport by wind: field studies at Owens Lake, California

Abstract

Field studies conducted at Owens Lake, California, provide direct measurements of sand flux on sand sheets with zero to 20 per cent cover of salt grass. Results from 12 different sand transport events show that aerodynamic roughness length and threshold wind shear velocity increase with vegetation cover as measured by vertically projected cover and roughness density (λ). This results in a negative exponential decrease in sediment flux with increasing vegetation cover such that sand transport is effectively eliminated when the vertically projected cover of salt grass is greater than 15 per cent. A general empirical model for the relation between sand flux and vegetation cover has been derived and can be used to predict the amount of vegetation required to stabilize sand dune areas.

Aeolian sediment transport on a human‐altered foredune

“…Detailed evaluations of roughness parameters associated with vegetation are difficult because of the complex shapes and heterogeneous clustering of plants (Lancaster and Baas, 1998;Arens et al, 2001), but qualitative evaluations of the role of vegetation can be made using visual estimates of key variables. Height of vegetation (an estimate of roughness) and percentage ground cover (an estimate of potential for entrainment of surface sediments) were measured in a 1 × 1 m grid between 12 and 20 March 2003.…”

Remote sensing and spatial analysis of aeolian sand dunes: A review and outlook

“…Field studies have demonstrated that the presence of vegetation effectively reduces aeolian sand transport, and vice versa (Ash and Wasson, 1983;Buckley, 1987;Wolfe and Nickling, 1993;Brown, 1997;Lancaster and Baas, 1998;Levin et al, 2008;Okin, 2008). The complex interplay and feedbacks between vegetation growth and sand transport drives the dune system towards one of the two end-member states: active or stabilized.…”

Migration of Barchan Dunes in Qatar–Controls of the Shamal, Teleconnections, Sea-Level Changes and Human Impact

“…In their exhaustive analysis on Quaternary stratigraphy and environments of the Arabian Peninsula, Glennie and Singhvi [51] confirm the long-term persistence of the Shamal, but state a generally weaker intensity during interglacials. While decreasing trends of the NAO and the ISM may indicate a Shamal stronger than today over most of the Holocene, and hence, higher migration rates, wetter conditions during the early to mid-Holocene transition identified in many parts of the Arabian Peninsula [50,[52][53][54] may have stimulated vegetation cover slowing down sand flux and migration speed [4,11,55,56]. The ways in which these competing mechanisms have led to deviations from the migration rates identified in the shorter term multitemporal satellite and aerial image analysis of this study over millennial time scales remain a matter of speculation.…”