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.