scholarly journals The character of windbreaks and their influence on mitigation of soil erosion

2016 ◽  
pp. 219-226 ◽  
Author(s):  
David Řehácek ◽  
Tomás Khel ◽  
Josef Kucera ◽  
Jan Vopravil ◽  
Martin Petera
Keyword(s):  
Wind Speed ◽  
Soil Cover ◽  
Leeward Side ◽  
Soil Protection ◽  
Speed Reduction ◽  
Speed Measurement ◽  
Ambulatory Measurement ◽  
Optical Porosity ◽  
Cultivated Plant ◽  
Wind Speed Measurement

Windbreaks create efficient soil protection against wind erosion particularly at the time when soil cover is not protected by vegetation cover of cultivated plant. The objective of this research was to find correlation between qualitative parameters of windbreaks and their efficiency in terms of wind speed reduction. The wind speed measurement was carried out by 4 stations along windbreak. The station contains 2 anemometers at heights 0.5 and 1 m above the surface. The character of windbreak was described by photogrammetry method as the value of optical porosity from the photo documentation of the windbreak at the time of ambulatory measurement. Important dependency between the value of optical porosity and efficiency of windbreak emerged from the results. An important protective effect of windbreak on soil was proven on the leeward side of the windbreak in the belt corresponding with approximately six times the height of the windbreaks.

scholarly journals Effect of windbreaks on wind speed reduction and soil protection against wind erosion

2017 ◽  
Vol 12 (No. 2) ◽  
pp. 128-135 ◽  
Author(s):  
D. Řeháček ◽  
T. Khel ◽  
J. Kučera ◽  
J. Vopravil ◽  
M. Petera
Keyword(s):  
Wind Speed ◽  
Wind Erosion ◽  
Statistical Significance ◽  
Polynomial Equation ◽  
Windward Side ◽  
Leeward Side ◽  
Soil Protection ◽  
Speed Reduction ◽  
Optical Porosity ◽  
Cultivated Plant

Windbreaks form efficient soil protection against wind erosion particularly at the time when soil cover is not protected by the cultivated plant vegetation cover. The objective of this research was to evaluate windbreaks efficiency in terms of wind speed reduction. Wind speed along the windbreaks was measured in the cadastral areas of Dobrovíz and Středokluky (Czech Republic, Central Europe). The measurement was carried out by 4 stations placed at windward side (1 station at the distance of 3 times the height of the windbreak) and at leeward side of the windbreak (3 stations at the distance of 3, 6, and 9 times the height of the windbreak). Each station contained 2 anemometers situated 0.5 and 1 m above surface. The character of windbreak was described by terrestrial photogrammetry method as the value of optical porosity from the photo documentation of the windbreak at the time of field measurement. A significant dependence between the value of optical porosity and efficiency of windbreak emerged from the results. The correlation coefficient between optical porosity and wind speed reduction was in the range of 0.842 to 0.936 (statistical significance more than 95%). A significant effect of windbreak on airflow reduction was proven on the leeward side of windbreak in a belt corresponding to approximately six times the height of the windbreaks depending on the optical porosity and it was expressed by a polynomial equation.  

scholarly journals The efficiency of windbreaks on the basis of wind field and optical porosity measurement

2008 ◽  
Vol 56 (4) ◽  
pp. 281-288 ◽  
Author(s):  
Tomáš Středa ◽  
Petra Malenová ◽  
Hana Pokladníková ◽  
Jaroslav Rožnovský
Keyword(s):  
Wind Speed ◽  
Wind Field ◽  
Close Relation ◽  
Horizontal Wind ◽  
Leeward Side ◽  
Profile Measurement ◽  
Average Wind Speed ◽  
Speed Reduction ◽  
Average Wind ◽  
Optical Porosity

Windbreaks have been used for many years to reduce wind speed as a wind-erosion control mea­su­re. To assessment of windbreak efficiency two main parameters are using: height of windbreak (H) and aerodynamic porosity. In South Moravian Region the total area of windbreaks is approximately 1200 ha. For purposes of horizontal profile measurement of wind speed and wind direction windbreaks with various spices composition, age and construction in cadastral territory Suchá Loz and Micmanice were chosen. Windbreak influence on horizontal wind profile was found out in distance of 50, 100, 150 and 200 m in front and behind windbreak in two-meter height above surface. For the optical porosity measurement the ImageTool program was used. The wind field measurement results of windbreak in Suchá Loz cadastral shows limited effect of windbreak on wind speed. The windbreak is created mainly by Canadian poplars (Populus × canadensis). In dependence on main species foliage stage the effect of windbreak was obvious on leeward side to distance of 100–150 m (c. 5–7 H). Average optical porosity of windbreak in Suchá Loz was 50% (April). Reduction of average wind speed was about 17% maximally in this stage. Optical porosity was 20% and wind speed reduction was about 37% during second measurement (October). The second monitored windbreak (Micmanice) had a significant influence on wind speed even to the maximal measured distance (200 m, c. 14 H). This windbreak crea­ted mainly by Acer sp. and Fraxinus excelsior reduced the wind speed about 64%. During first measurement (May) the optical porosity of 20% and maximal wind speed reduction of 64% were assessed. For optical porosity of 21% (October) the wind speed reduction was about 55%. Close relation between optical porosity and wind speed reduction was found out by statistical evaluation. Correlation coefficient regardless locality for distance of 50 m was −0.80, 100 m −0.92, 150 m −0.76 and for distance of 200 m −0.63.

Determining permissible Doppler lidar beam deviation angles in wind speed measurement

1991 ◽  
Vol 34 (9) ◽  
pp. 906-911
Author(s):  
A. A. Kormakov ◽  
L. A. Kosovskii ◽  
N. V. Pakhomushkina ◽  
G. A. Pogosov
Keyword(s):  
Wind Speed ◽  
Doppler Lidar ◽  
Speed Measurement ◽  
Wind Speed Measurement

Wind speed measurement

1987 ◽  
Vol 81 (6) ◽  
pp. 2001-2001
Author(s):  
Maurice C. Heard
Keyword(s):  
Wind Speed ◽  
Speed Measurement ◽  
Wind Speed Measurement

Improvement of Wind Speed Measurement Model by Meteorological UAV and System Design

2012 ◽  
Vol 542-543 ◽  
pp. 591-594
Author(s):  
Shu Dao Zhou ◽  
Yong Qi Jin ◽  
Ying Qiang Wang ◽  
Min Wang
Keyword(s):  
Wind Speed ◽  
System Design ◽  
Measurement System ◽  
Measurement Model ◽  
Calculation Model ◽  
Related Data ◽  
Speed Measurement ◽  
Design Diagram ◽  
Wind Speed Measurement ◽  
The Impact

At present, the error of wind speed measurement by meteorological UAV is great, in order to solve this problem, this paper identified the major sources of error by the analysis of the wind measurement model. Found that the airspeed error caused by the aircraft acceleration for the airspeed is very small, so classic airspeed measurement calculations often ignore the impact of aircraft acceleration, but the value of wind speed is smaller, so that the error caused by aircraft acceleration relative to the wind speed cannot be ignored. Therefore, this article added aircraft acceleration to re-establish the airspeed measurement model, and got an improved wind speed of calculation model. In order to verify the model, the wind speed measurement system was been designed, the system design diagram and related data processing, solver method were presented.

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