基于GIS的兰新铁路沿线风沙灾害致灾成因分析及评价

Evaluation and Analysis of the Causes of Wind-sand Disaster along Lanzhou-Urumqi Railway Based on GIS

风沙灾害地域性强,具有防治难度大、周期长等特点。为减轻风沙灾害对铁路的危害,以兰新铁路沿线的遥感数据和实测数据为基础,利用层次分析法确定风速、植被、海拔、坡向、干燥度、地表粗糙度与风沙灾害的权重关系,并采用多因子评价模型对兰新铁路沿线风沙灾害易发性进行评估。研究结果表明:风沙灾害评价中,植被指标作用最为显著,其次为风力;风沙灾害重度区主要位于阿拉山口、达坂城、百里风区和烟墩风区,中度区主要位于精河县境内临近艾比湖区域;与近50年兰新铁路沿线风沙灾害发育情况相比,分析结果具有较好的一致性。

Wind-sand disaster has the characteristics of strong territoriality, great difficulty and long period in prevention and control. Based on remote sensing data and measured data along Lanzhou-Urumqi Railway, this paper determines the weight relationship between wind speed, vegetation, altitude, slope direction, dryness, surface roughness and wind-sand disaster by using analytic hierarchy process(AHP), and evaluates the risk of wind-sand disaster along the railway by using multi-factor evaluation model. The results show that vegetation index plays the most significant role, followed by wind power. The severe wind-sand disaster areas are mainly located in Alashankou, Dabancheng, 100 km wind area and Yandun Wind Area;and the moderate areas are concentrated near Aibi Lake in Jinghe County. Compared with the development situation of wind-sand disaster along Lanzhou-Urumqi Railway in the last 50 years, the analysis results have good consistency.