北京周边地区沙尘暴时空分布特征及其环境背景

以 195 1～ 1996年地面气象记录、 90年代末TM影像为主要数据源 ,运用气候统计学方法 ,在地理信息系统技术的支持下分析了近 5 0年北京周边地区 (即华北北部 )沙尘暴的时空变化特征及其区域差异 ,结合遥感影像提取的土地利用和土壤侵蚀信息 ,分析了沙尘暴形成的生态环境背景。结果表明 :沙尘暴高值区位于浑善达克沙地和库布齐沙地的周边 ,特别是西北部的四子王旗 -苏尼特右旗朱日和、二连浩特市 -达茂旗满都拉和达拉特旗 -准格尔旗-乌拉特中旗。从时间变化看 ,午后至傍晚是沙尘暴天气易发的高峰期 ;季节变化总体上春季较多 ,其次是夏季和初秋 ;从年际变化看 ,5 0～ 6 0年代是沙尘暴发生的高值期 ,70～ 80年代在波动中呈减少趋势 ,进入 90年代后又呈上升趋势 ,多发期与干冷气候期相对应。

Spatial and temporal distribution characteristics of sand-dust storms around Beijing Region

In North China, an unprecedented heavy sand-stormy weather with high frequency took place in the spring of 2000. Dramatically, it brought direct damage to the region around Beijing, which has aroused even more extensive concern of personages of various circles. Sand-stormy weather research has been widely carried out since then. Therefore, in this paper, based on the climate data from 1951 to 1996 and eco-environmental data, employing climate statistics methods and geographic information sciences(GIS), the author took the land around Beijing as a case to study its characters of the temporal and spatial pattern in the past fifty years. The annual sand-dust storms day was selected as the major index to divide the region into four districts, then the environmental background was analyzed based on data extracted from the remote sensing images of the 1990s. This research demonstrated the spatial distribution and temporal change of sand-dust storms in this area, leading to the following conclusions: diurnally, afternoon(from 12 p.m.to 18 p.m.)was the period of sand-dust storms;seasonally spring and late summer were the sand-dust storms most easily happening periods;interannually,the 1950s to the 1960s witnessed the high value period of the sand-dust storms while the number of the sand-dust storm days tended to reduce in the 1970s and the 1980s but increased in the 1990s again. We also found that the most easily happening period corresponded to the dry and cold climate. As for the spatial distribution, the high value regions were located in the marginal areas of Otindag Sandy Land and Hobq Sandy Land, especially in Siziwangqi-Zhurihe, Erenhot-Damaoqi, Daladqi-Junggarqi-Uradqi.