Characteristics of the disastrous wind-sand environment along railways in the Gobi area of Xinjiang, China
Based on detailed long-term data of wind regimes collected from typical ventilation sites along the railways in the Gobi area of Xinjiang, this study systematically analyzes the characteristics of the disastrous wind-sand environment along the railways by combining gradient sand sampling data collected by a wind-drift sand monitoring system and site survey data. Wind direction and speed rose diagrams revealed the prevailing wind direction in each wind area along the railways, and this is the wind direction from which the maximum frequency of sandstorms occurred. Drift potential characteristic parameters (RDP, RDD) and the direction variability (RDP/DP) showed that each wind area along the Gobi railway featured a long wind period, with strong power in a single wind direction. The special geological environment of the Gobi determines the wind-drift sand that features gravel of large grain size and unsaturation, which are different from the wind-drift sand in deserts. With increasing wind velocity, the density of the wind-drift sand increased steadily; however, at a certain critical value, the density surged. This study on the wind-sand environment of the Gobi has significance for railway safety. The critical value of wind velocity corresponded to an abrupt increase in the wind-drift sand density and should be taken into account during the planning process of railway safety passage, since this will lead to a decrease in frontal visual distance, and an associated decrease in safety. Additionally, the specific features of wind-drift sand activities, such as the abruptness and higher than usual sand height, should be considered during the process of designing sand-damage-control engineering measures.