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| Titel |
How Efficient is Vegetation in Reducing Wind Erosion and Emission of Health-Threatening Fine Dust PM10? - A Wind Tunnel Approach |
| VerfasserIn |
K. Burri, F. Graf |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250022650
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| Zusammenfassung |
| World wide, wind erosion and desertification are most alarming processes of environmental
degradation. Not only do they cause tremendous losses of fertile soil, but they also seriously
affect human health. Pulmonary tuberculosis (silicosis) is one of the major diseases that have
been linked to mineral fine dust (PM10) in the atmosphere.
It is widely accepted that the re-establishment of an intact vegetation cover is the most
effective measure against wind erosion. However, despite numerous investigations, the
mechanisms responsible for the protective effect of vegetation are still not completely
understood. Since the phenomenon involves highly variable interactions between soil, plants
and atmosphere, it is particularly difficult to quantify the efficiency of vegetation
in reducing wind erosion. As an alternative to field investigations, wind tunnel
experiments offer the advantage to control specific parameters within this highly complex
system.
In this study, a series of wind tunnel experiments was performed including measurements
of sediment transport and PM10 emission in differently dense grass canopies of Lolium
perenne (91, 24, 5 and 0 plants per square meter). The novelty of the present wind tunnel
study is the use of living plants instead of artificial imitations or dead plant parts. Although
more and more sophisticated imitations of vegetation have been used in recent studies, the
behaviour of living plants is likely to differ significantly. Coloured quartz sand was used for
visualizing sand erosion and deposition patterns. The vertical profiles of aeolian sediment
flux were analysed with a stackable sediment sampler composed of 60 collecting boxes, each
with a height of 1 cm.
The results of this study confirm that both sediment transport and PM10 emission strongly
decrease with increasing plant cover. The protective effect of the plants was found to be
linked to characteristic changes in the vertical profile of aeolian sediment flux and to specific
spatial patterns of sediment deposition. Furthermore, observations indicate that the
performance of plants in wind erosion control strongly depends on plant species specific
characteristics, particularly growth form and stiffness, as well as on their physiological
state.
The use of living plants in wind tunnel experiments offers the possibility to study a wide
range of more specific aspects of biological wind erosion control. As a next step it is planned
to test the effect of mycorrhizal fungi on the wind erodibility of vegetated soil systems. |
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