Field scale spatio-temporal variability of wind erosion transport capacity and soil loss at Urmia Lake

Urmia Lake has been known as the second hypersaline lake in the world, with the surface area of approximately 5200 km(2). With decreasing the water input of the lake due to anthropogenic activities, the susceptible areas to wind erosion and dust emission were extended during the last decades. The present study attempted to measure wind erosion on the edge of Urmia Lake for three years since 2017. In order to provide a quantitative under-standing of wind erosion parameters in the dried up Urmia Lake area, and to prioritize different areas in terms of wind erosion intensity, it was necessary to establish wind erosion measurement and monitoring stations in different areas of dried up shores. Wind erosion measurement and monitoring stations were established in six erodible areas such as Salmas, Jabal Kandi, Soporghan, Miandoab, Khaselou and Ajabshir. Wind erosion parameters such as transport capacity and soil loss in the dried margin of Urmia Lake were determined. For this purpose, BSNE traps were used in the layout of two circles having an identical center. After each wind erosion event, sediment traps were emptied and weighted; then, the vertical and horizontal distribution of the particulate matters was calculated. Comparison of the values of maximum transport capacity-f(max) (kg/m.yr) and soil loss-SL (ton/ha.yr) of aeolian particulate in 2017 showed that the two main centers of wind erosion on the edge of Urmia Lake were Ajabshir and Jabal Kandi. The stations of Khaselou, Salmas, Soporghan and Mianduab were in the declined ranking. Results showed that the transfer capacity values were 351.97 and 297.30 kg/m/year and soil losses were 18.04 and 35.4 ton/ha/year, respectively, for the stations with high wind erosion potential, i.e., Ajab Shir and Jabal Kandi, in 2017. Furthermore, these values were significantly reduced for the mentioned stations in 2019, so that the values obtained from the transfer capacity reached 54.93 and 40.39 kg/m/year and soil losses reached 3.70 and 2.43 ton/ha. Investigating the results of transport capacity and soil loss showed the decreasing trend in wind erosion rate due to the increasing water level of the lake as well as biological and engineering conservation practices (non-live windbreaks) from 2017 to 2019.

Automated summary

Urmia Lake, the second hypersaline lake in the world, has experienced an increase in susceptible areas to wind erosion due to decreasing water input caused by human activities. The study found that wind erosion on the edge of Urmia Lake was influenced by the water level of the lake and conservation practices, resulting in a decreasing trend in wind erosion rate from 2017 to 2019.