2000年华北沙尘天气遥感研究

Remote Sensing Study on the Dust Storm Stricking North China in 2000

利用最新的气象卫星数据分析影响华北的沙尘天气从产生到消失的动力过程 ,确定了沙尘天气发生的范围和移动方向。并利用TM、NOAA、FY 1影像 ,时间跨度为 30年的沙尘暴空间分布数据 ,195 1— 1994年华北地区的气象站点数据 ,土壤质地和土地利用数据 ,对沙尘天气发生的下垫面因素与沙尘天气发生的空间分布关系进行了分析 ,指出植被指数、土壤质地、土壤含水量和地形对沙尘天气发生的影响方式 ,并对沙尘天气发生区域的土壤侵蚀状况进行了分析 ,探讨了影响华北地区沙尘天气的供沙区分布状况和不同路径沙尘暴的源地分布 ,结果表明下垫面因素对于沙尘天气的产生有着非常重要的作用。

The paper based on the data as following: ① the TM, NOAA, FY 1 image data; ② the dust storm data dated from 1951\_1980; ③ meteorological statistic data dated from 1951\_1994; ④ soil property; ⑤ land use data. Using the RS/GIS method, all the data are processed to describe the spatial distribution of sand dust storm. The dynamic process of the sand dust storm is analyzed, and the results show that the air circulation of northern China causes the special wind field accompanied with which the sand supplying areas and sand descending areas are identified out. Up to date meteorological satellite data are used to analyze the trajectories of the sand dust storms that have influenced the north China during the spring of 2000, including its out bursting places and moving direction. Also the spatial distribution of sand dust storm from 1951 to 1980 has been analyzed.\ \ The regions that have varied annual total days of sand dust storm are identified out. The results show that from northwest to southeast, the frequency of sand dust storm is decreasing with the most serious area lying to the northwest and west of North China.\;The analysis work of the spatial distribution of main factors that influence the sand supplying of the surface soil are carried out as well as their relation to the frequency distribution of sand dust storm. These factors include the vegetation coverage, soil surface water content, soil property, geomorphologic factor and the land use. Each factor shows high relationship with the frequency distribution of sand dust storm.\;Then the results of remote sensing investigation of wind erosion are analyzed showing that the intensity of wind erosion is decreasing from northwest to southeast with the middle part of Inner Mongolia as the most seriously eroded area. At last, the sand supplying information of the land to the dust storm is revised. The area where the wind intensity strengthens, its frequency of annual dust storm also increases, vice versa. It seems that all these areas are possibly supplying the sand when the sand dust storm happens. There are mainly three routes for the sand dust storm, however the dust storm that has different routes also has varied sand supplying places as pointed out in the paper.