1. School of Soil and Water Conservation, Key Laboratory of State Forestry Administration on Soil and Water Conservation, Beijing Forestry University, 100083, Beijing, China;
2. Yanchi Ecology Research Station of the Mu Us Desert, 751500, Yanchi, Ningxia, China
Abstract：[Background] The Qinghai-Tibet Railway (QTR) runs 1956 km from Xining to Lhasa. It is the longest altiplano railway in the world and at the highest altitude. It is also a central project in the strategy of "Western Development" in China. However, the QTR has been under constant threat from aeolian sand since its opening, and the Nanshankou section is one of the worst areas along the railway line. In order to build a scientific and efficient protection system against wind-sand disaster in Nanshankou, we conducted field investigation and wind tunnel experiment to reveal the mechanism of wind sand disasters.[Methods] The allocation model of protection system and volume of sand sediment around railway line was measured through the field investigation. Taking the roadbed and control measures as prototypes, scaled models were made for wind tunnel simulation. The speed of inflow in wind tunnel was kept at 15 m/s,which was highest frequency during the local windy season. And the KIMO hotwire anemometer was used to measure the wind speed in the working section of wind tunnel. The simulation research was made up of three parts:We firstly observed the flow field around the simulated roadbed to explore the vulnerability of the roadbed to windblown sand. Then, the simulated control measures was disposed around the roadbed to reveal the influence of current protection system on flow field. Finally, the efficiency and defects of current protection system were analyzed based on the modification simulation and distribution of sand sediment.[Results] The results indicate that:1) Roadbed was an obviously obstacle in Nanshankou. The low-speed area occurred at the foot of windward slope, and the high-speed area occurred at the shoulder of windward side and the top of roadbed. These two areas were respectively responsible for sand deposition and wind erosion, harming the safety of the QTR. 2) In the current protection system, the distance between PE fences were 19 m and 20 m, respectively. It is too far for sediment precipitation. Hence, the sand sediment proportion blocked by the second and third PE fence was only 2.42% and 0.24%, respectively. 3) The wind tunnel experiment recommended that, the distance between each PE fence should be reduced to increase the efficiency. More sleeper typed fences should be added to the west side of current protection system to increase the width of protection distance and block the sand at outer space as much as possible.[Conclusions] This study reveal the characteristics of windblown sand near the railway, we put forward and discussed the possible improvement program. These improved information are essential to provide a firm basis for desertification control along the QTR, and the results of this paper may also be used in other areas where experience threats from windblown sand.
谢胜波, 屈建军. 青藏铁路主要沙害路段治理技术及成效[J]. 干旱区资源与环境, 2014, 28(7):105. XIE Shengbo, QU Jianjun. Sand damage control and effect at main sections of Qinghai-Tibet railway[J]. Journal of Arid Land Resources and Environment, 2014, 28(7):105.
[2]
LIU Zhimin, ZHAO Wenzhi. Shifting-sand control in central Tibet[J]. Ambio, 2015, 30(6):376.
[3]
ZHANG Kecun, QU Jianjun, LIAO Kongtai, et al. Damage by wind-blown sand and its control along Qinghai-Tibet railway in China[J]. Aeolian Research, 2010, 1(3/4):143.
[4]
谢胜波, 屈建军, 刘冰, 等. 青藏铁路沙害及其防治研究进展[J]. 中国沙漠, 2014, 34(1):42. XIE Shengbo, QU Jianjun, LIU Bing, et al. Advances on research on the sand hazards and its controls along the Qinghai-Tibet railway[J]. Journal of Desert Research, 2014, 34(1):42.
[5]
XIE Shengbo, QU Jianjun, XU Xiangtian, et al. Interactions between freeze-thaw actions, wind erosion desertification, and permafrost in the Qinghai-Tibet Plateau[J]. Natural Hazards, 2017, 85(2):829.
[6]
ZHANG Kecun, QU Jianjun, NIU Qinghe, et al. Characteristics of wind-blown sand and dynamic environment in the section of Wudaoliang-Tuotuo River along the Qinghai-Tibet Railway[J]. Environmental Earth Sciences, 2011, 64(8):2039.
[7]
XIE Shengbo, QU Jianjun, LAI Yuanming, et al. Formation mechanism and suitable controlling pattern of sand hazards at Honglianghe River section of Qinghai-Tibet Railway[J]. Natural Hazards, 2015, 76(2):855.
[8]
XIAO Jianhua, YAO Zhengyi, QU Jianjun. Influence of Golmud-Lhasa Section of Qinghai-Tibet Railway on blown sand transport[J]. Chinese Geographical Science, 2015, 25(1):39.
[9]
牛清河, 屈建军, 张克存, 等. 青藏铁路典型路段风沙灾害现状与机械防沙效益估算[J]. 中国沙漠, 2009, 29(4):596. NIU Qinghe, QU Jianjun, ZHANG Kecun, et al. Status of aeolian-sand disaster and estimation of mechanical sand-controlling benefit at typical sections of Qinghai-Tibet Railway[J]. Journal of Desert Research, 2009,29(4):596.
[10]
白虎志, 李栋梁, 董安祥, 等. 青藏铁路沿线的大风特征及风压研究[J]. 冰川冻土, 2005, 27(1):111. BAI Zhihu, LI Dongliang, DONG Anxiang, et al.Strong wind and wind pressure along the Qinghai-Tibet Railway[J]. Journal of Glaciology and Geocryology, 2005, 27(1):111.
[11]
ZHOU Jinxing, YANG Jun, PENG Gong. Constructing a green railway on the Tibet Plateau:Evaluating the effectiveness of mitigation measures[J]. Transportation Research Part D Transport & Environment, 2008, 13(6):369.
[12]
姜鑫贵, 周金星, 刘玉国, 等. 青藏铁路南山口段沙害防治措施的效果[J]. 林业科学, 2016, 52(10):55. JIANG Xingui, ZHOU Jinxing, LIU Yuguo, et al.Effectiveness of sand control measures in Nanshankou Area along Qinghai-Tibet Railway[J]. Scientia Silvae Sinicae, 2016, 52(10):55.
[13]
范基姣, 谭立渭, 佟元清. 青藏铁路沿线格尔木-南山口段环境地质评价[J]. 中国人口·资源与环境, 2011, 21(3):288. FAN Jijiao, TAN Liwei, TONG Yuanqing.Environmental geology assessment of Qinghai-Tibet railway from golmud to south mountains pass using AHP-FUZZY method[J]. China Population,Resources and Environment, 2011, 21(3):288.
[14]
谢胜波, 屈建军, 刘冰,等. 青藏铁路沙害及其防治研究进展[J]. 中国沙漠, 2014, 34(1):42. XIE Shengbo, QU Jianjun, LIU Bing, et al. Advances in research on the sand hazards and its controls along the Qinghai-Tibet railway[J]. Journal of Desert Research, 2014, 34(1):42.
2018, Vol. 16 
