Influence of reed stem density on foredune development

TY - JOUR

T1 - Influence of reed stem density on foredune development

AU - Arens, SM

AU - Baas, ACW

AU - Van Boxel, JH

AU - Kalkman, C

PY - 2001/10

Y1 - 2001/10

N2 - Vegetation density on foredunes exerts an important control on aeolian sediment transport and deposition, and therefore on profile development. In a long-term monitoring field experiment, three plots were planted with regular grids of reed bundles in three different densities: 4, 2 and 1 bundles per m(2). This study reports on the differences in profile development under the range of vegetation densities. Topographic profiles were measured between May 1996 and April 1997. Results indicate important differences in profile development for the three reed bundle densities: in the highest density plot a distinct, steep dune developed, while in the lowest density a more gradual and smooth sand ramp was deposited. When the stems had been completely buried, differences in profile evolution vanished. After a second planting of reed stems in January 1997 the process was repeated. In May 1997, all plots had gained a sand volume ranging from 11.5 to 12.3 m(3) m(-1), indicating that the sediment budget is relatively constant, regardless of the particular profile evolution. The field evidence is compared with simulations of profile development, generated by the foredune development model SAFE. The model successfully reproduces the overall profile development, but in general, the equations used for vegetation-transport interaction overestimate the effect of vegetation. This causes some deviations between field and model results. Several reasons for this are discussed. Based on the experiments reported here, recommendations are given for further research.

AB - Vegetation density on foredunes exerts an important control on aeolian sediment transport and deposition, and therefore on profile development. In a long-term monitoring field experiment, three plots were planted with regular grids of reed bundles in three different densities: 4, 2 and 1 bundles per m(2). This study reports on the differences in profile development under the range of vegetation densities. Topographic profiles were measured between May 1996 and April 1997. Results indicate important differences in profile development for the three reed bundle densities: in the highest density plot a distinct, steep dune developed, while in the lowest density a more gradual and smooth sand ramp was deposited. When the stems had been completely buried, differences in profile evolution vanished. After a second planting of reed stems in January 1997 the process was repeated. In May 1997, all plots had gained a sand volume ranging from 11.5 to 12.3 m(3) m(-1), indicating that the sediment budget is relatively constant, regardless of the particular profile evolution. The field evidence is compared with simulations of profile development, generated by the foredune development model SAFE. The model successfully reproduces the overall profile development, but in general, the equations used for vegetation-transport interaction overestimate the effect of vegetation. This causes some deviations between field and model results. Several reasons for this are discussed. Based on the experiments reported here, recommendations are given for further research.

KW - vegetation density

KW - aeolian processes

KW - modelling

KW - roughness elements

KW - adaptation length

KW - WIND EROSION

KW - VEGETATION COVER

KW - SAND TRANSPORT

KW - SPARSE VEGETATION

KW - FIELD MEASUREMENT

KW - AEOLIAN PROCESSES

KW - TRANSVERSE DUNES

KW - SALTATION

KW - SURFACES

KW - DESERT

U2 - 10.1002/esp.257

DO - 10.1002/esp.257

M3 - Article

SN - 1096-9837

VL - 26

SP - 1161

EP - 1176

JO - EARTH SURFACE PROCESSES AND LANDFORMS

JF - EARTH SURFACE PROCESSES AND LANDFORMS

IS - 11

M1 - N/A

ER -