2015年西藏日喀则市和阿里地区雪灾遥感监测评价

Remote Sensing Monitoring and Evaluation of Snow Disasters in Xigaze City and Ngari Area of Tibet in 2015

文章结合遥感与地理信息系统,以MODIS数据得到的归一化雪盖指数(NDSI)为基础,对2015年1月9日主要发生在西藏日喀则市和阿里地区一次大雪灾进行了积雪面积、持续时间和动态变化的监测与评估。研究结果表明:(1)积雪深度最大时统计的积雪覆盖面积远远大于雪灾减弱时的面积;(2)基于遥感监测可以准确得知强降雪前后积雪覆盖面积、积雪具体覆盖位置以及降雪持续时间,从而可以推断强降雪过程所造成的灾害的大小;(3)使用卫星云图非全部是晴空图时,分析数据存在偏差。

Monitoring and evaluation on snow coverage,snow duration and dynamic during the heavy snowstorm in January 9 th year 2015 in Shigatse and Ali areas of Tibe were done based on the Normalized Snow Cover Index(NDSI)obtained from MODIS data combined with Remote Sensing and Geographic Information System(GIS).The reslts showed that(1)the snow cover area calculated when the maximum snow depth was much larger than the area when the snow disaster weakening,(2)remote sensing monitoring can accurately detect the area of snow cover before and after heavy snowfall,the specific location of snow cover,and the duration of snowfall so that the magnitude of the disaster caused by the heavy snowfall process can be inferred as well,(3)when the satellite cloud image is not all clear-sky maps,there is a deviation in the analysis data.