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WİND EROSION MEASUREMENT: Karapınar case study
, Ali Uğur Özcan1, Oğuzhan Uzun2, Selen Saygın Deviren3, Feras Youssef3 , Mustafa Başaran2 , Günay Erpul3
1. Çankırı Karatekin University, Faculty of Forest, Department of Landscape Architecture, Çankırı, Turkey2. Erciyes University, Faculty of Agriculture, Department of Soil Science, Kayseri, Turkey3. Ankara University, Faculty of Agriculture, Department of Soil Science, Ankara, Turkey
Wind Erosion
• Wind erosion is one of the most important reasons of desertification in semi-arid regions
• It is estimated that, nearly 500 million hectare areas have been degraded by wind erosion (UNEP and ISRIC, 1990; REICH et al., 2000 ).
• The area influenced by wind erosion is 465.000 hectar in Turkiye (ACAR, 2010)
Wind erosion
Soil dust: • atmospheric composition and climate change, • transport of herbicides on sediments, • soil texture, • nutrient content, • vegetation growth and productivity • animal and human health
The Main Reason?
CHANGES IN LAND USES
Wetlands Forests
Agricultural areasGrasslands
How is wind erosion measured?
– Management decisions should be taken depending on wind erosion magnitude and related paramaters for sensitive erosive areas
Principally, erosion strength and the areas that affected by erosion should be determined by direct measurements in the field!!!!!
Direct measurement
• The effective traps were improved for catching sediments:– Active traps– Passive traps
• Wilson and Cook (WAC)• Big Spring Number Eight (BSNE)• Basaran and Erpul Sediment Trap (BEST)
– Piezo electric sensors• Saltiphone• Sensit
Direct measurementPassive Traps
Basaran and Erpul Sediment Trap (BEST)
It is a new design trap
For <100 µm particles, its efficiency is 0.80
Its efficiency is 0.90 in field surveys
It has a plastic body
It is cheap and easy to set up
Study Area
Climate properties;• Terrestrial • Average temperature is 10.1 oC• Average precipitation is 279.56
mm• Main wind direction is North
(South and Southwest aspects are mostly cause erosion events in area)
• Wind speeds can be higher than 25 ms-1 in area.
Soil properties; • Top soil texture is loamy
sand and clay contents gets increased in sub layers
• It has high calcium carbonate and potassium,
• it has low organic matter and phosphorus
• Location: Karapınar, Konya-TURKIYE
In the research field, 7 plots which have different surface conditions were chosen
Plots
Direct measurementsKarapınar
In this research, high efficiency BEST Traps were used
Direct measurementsKarapınar
Best Traps were located on the winged pole with 5 different heights
( 20,40,60,80,100cm)
Direct measurementsKarapınar
20 wind erosion measurement set-up were located like a grid shape or random
Direct measurementsKarapınar
Climate datas were recorded by meteorology station which located next to plot area
Data analysisKarapınar
Wind erosion event occurred four times between March and April in field survey
After each event, sediment that was cought by BEST traps was collected and weighed with sensitive balance.
Data analysisKarapınar
Sediment flux (kg m-2 h-1 ) was modeled with exponential model for each event in each two plots (Eq1 and Eq2). İn two plots, for total 8 wind erosion events, 160 mathematical models were done:
zbmaeSF Eq. (1)
z
0
dzSASFR Eq. (2)
With saltiphone, each event duration was measured and ratio of sediment flux was calculated from each point of 1 m height
On the plot basis, for each wind erosion event, sediment flux ratio was assessed with geostatistical methods.
Data analysisA. Plot
1. Event : Averg Wind Velocity: 6.7 m/sn Wind Direction: Northeast- SouthwestEvent times: 3 hoursSAO: 0.102 kg m-1 h-1
2. Event : Averg Wind Velocity: 7 m/sn Wind Direction: East-WestEvent times: 8 hoursSAO:0.024 kg m-1 h-1
3. Event : Averg Wind Velocity: 6.9 m/sn Wind Direction: Southwest- Northeast Event times: 7 hoursSAO: 0.077 kg m-1 h-1
4. Event : Averg Wind Velocity: 6.3 m/sn Wind Direction: kuzey-güneyEvent times: 1 hourSAO:0.178 kg m-1 h-1
Data analysisB. Plot
1. Event : Averg. wind velocity: 6.7 m/sn Wind direction: Northeast- SouthwestEvent times: 3 hoursSFR: 0.146 kg m-1 h-1
2. Event : Averg. wind velocity: 7 m/sn Wind direction: East-WestEvent times: 8 hoursSFR:0.014 kg m-1 h-1
3. Event : Averg. wind velocity: 6.9 m/sn Wind direction: Southwest- Northeast Event times: 7 hoursSFR: 0.077 kg m-1 h-1
AssessmentKarapınar• Wind erosion affected areas should be determined in
Turkey.
• Event based losses should be measured by direct measurements and scaling should be done for risk areas.
• Climate, vegetation and soil properties relevant to wind erosion in wind erosion affected areas.
• External factors that raised risk (tillage, grazing, irrigation, forest management, etc.) should be defined in specific areas.
• Wind erosion should be monitored in Turkey and estimated models should be improved for the territorial or regional scale.
THANKS FOR ATTENTION
AcknowledgementAuthors gratefully acknowledge the “The Scientific and Technological Research Council of Turkey” (TUBITAK) for providing support within the frame of the project of TOVAG 110O296.