Hamidreza Abassi; mohammad kashki; Mohammad Reza Rahdari; azade gohardoust; Sakineh Lotfi Nasab Asl
Volume 27, Issue 2 , June 2020, , Pages 371-384
Abstract
The purpose of this study was to investigate the characteristics of wind regime and sand transport potential in the Sarakhs Erg, located in the north-eastern corner of Iran. Accordingly, using the data of wind speed and direction (1978-2016) of the Sarakhs synoptic station, the potential of sand transport ...
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The purpose of this study was to investigate the characteristics of wind regime and sand transport potential in the Sarakhs Erg, located in the north-eastern corner of Iran. Accordingly, using the data of wind speed and direction (1978-2016) of the Sarakhs synoptic station, the potential of sand transport (DP), Resultant Drift Potential (RDP), Resultant Direction Drift (RDD), and the ratio of RDP/DP were calculated using Fryberger-Dean (1979) method. Also, the characteristics of erosive winds and temporal changes were investigated based on sand transport (DP) potential. The results showed that the dominant wind direction and the sandy wind were northwest. Agricultural lands, especially in the fall season, as well as the sediments of the Tajan Border River, were the sources of wind sediments. In general, wind energy in the Sarakhs region based on the sand transport (DP) potential is put in the low class (DP=193 v.u) with the highest and the lowest in July and November, respectively. On the other hand, sand discharge capacity based on the average sand carrying potential (DP = 193 v.u) for this range was estimated to be about 13.51 m3 in width. Field studies and satellite images showed that sand and nebka zones were two main forms of wind sediments in Sarakhs Erg sediments.
Mohammadreza Rahdari; Hasan Ahmadi; Ali Tavili; Mohammad Jafari; Aliakbar Nazari Samani; mohammad khosroshahi; Shahrooz Sharifi
Volume 26, Issue 1 , June 2019, , Pages 226-240
Abstract
Due to vast desert area in Iran, wind regime studies are important for the railway safe design as well as aeolian sediment transport. In this study wind regime and sand drift potential (DP) were calculated with Fryberger method in nine meteorological stations located near to the Qom –Tehran railway ...
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Due to vast desert area in Iran, wind regime studies are important for the railway safe design as well as aeolian sediment transport. In this study wind regime and sand drift potential (DP) were calculated with Fryberger method in nine meteorological stations located near to the Qom –Tehran railway (178 km). For this reason, hourly wind speed and direction data were analyzed. Annual wind roses showed that West and Northwest winds were predominantly about 40%, 50%, 42% and 57% at the stations of Tehran, Shahriyar, Qom, and Imam Khomeini airport, respectively. The highest amount of sand drift potential was at the Imam Airport station (DP= 574, UDI=0.8) in the west and its lowest value was at Qom station (DP= 109, UDI= 0.47) in the south of the region. The drift potential (DP) for aeolian deposits was generally high (DP >400) in the Garmsar (DP= 481), Salafchegan (DP= 485), Saveh (DP= 552) and Imam Khomini airport (DP=574) climatological stations. DP was relatively moderate (200>DP>400) at the Shariyar and Kahak stations in the northwest and south of study area, respectively; and weak (DP<200) in the Tehran and Qom climatological stations. There was an increasing trend in the transport of sand when moving from Namakzar railway station to the Imam Khomeini railway station. Also field evaluations indicated the sensitivity of the Separ Rostam-Namakzar block to entry of sand, which was 21.3 kilometers long. Finally, it is suggested to railway directors of the Islamic Republic of Iran to proceed with the assessment of sand drift potential near railways station for control of sand deposition.