Amiri et al
Greener Journal of Physical Sciences Vol. 2 (4), pp. 141-147, October, 2012.
ISSN: 2276-7851 © 2011 Greener Journals
Turbulent Velocity Fluctuations as Affected by Biotic and Abiotic Windbreaks under Field Conditions
Iraj Amiri1, Javad Taei2*, Mohammad Reza Ekhtesasi3
and Ali Reza Shahryari4
1Department of Natural Resources, Faculty of Agriculture, University Of Jiroft, Jiroft, Iran
2Department of plant sciences, Faculty of Agriculture, University Of Jiroft, Jiroft, Iran
3Faculty of Natural Resources, Yazd University, Yazd, Iran
4Faculty of Natural Resources, University Of Zabol, Zabol, Iran
*Corresponding Author’s E-mail: ga_agric @yahoo. com
Windbreaks have been used for centuries to shelter crops
from wind damage and to protect soils from wind erosion.
This study was performed in 5 steps to evaluate the effects
of biotic and abiotic windbreaks on mean horizontal flow and
turbulent velocity fluctuations under field conditions.
These steps included granolometery analyzing, determination
of field threshold velocity of soil erosion, estimation of
acceptable wind speed, optimizing windbreak distance and
wind speed recording. Two kinds of windbreaks were used in
this study, biotic windbreak (Tamarix aphylla) with
45% density and abiotic windbreak (Mud wall) with 100%
density. Results of field experiment showed that optimized
distances for abiotic and biotic windbreak are respectively
observed at 7.87h and 4.5h after windbreak. Finally mud wall
is applicable for high decreasing wind speed at the back of
windbreak but its high wind speed fluctuation and high
turbulence were limited to these windbreaks in agro
ecosystem. Tamarix aphylla with 45% density is
applicable for medium decreasing of wind speed and creating
low turbulence after windbreak.
Keywords: Mud wall, Tamarix aphylla, threshold velocity, windbreak, Wind.