Abstract:

 Based on the surface meteorological observation data and dust event days from X70 stations in China from 1951 to 2000,the spatial dis-
tribution of dust storm,sand blowing,dust in January, April, July, events originate mainly from both the Northwest and the North of China, there arc three regions where the dust events occur frequently, which
arc Hexi corridor and Alashan plateau with the center of Mingqin county; the southern edge of Tarim basin with the center of Hetian; the mid-
dle part of Inner Mongolia with the center of Zhurihe. In addition, there is another region with the center of both Ningxia Yanchi and Etuokc
area of Inner Mongolia, where dust storm occurred frequently too. (hhe spatial distributions of dust storm, sand blowing, dust arc basically co-
incident. 'hhen, according to surface meteorological data, the relations between dust events distribution and surface meteorological elements have
been studied in this paper. 'hhc rasults arc as follows;the corrclations between dust events and precipitation,rclativc humidity as well as vegeta-
tion coverage rate arc obviously negative, and the correlation between dust events and evaporation is positive. "hhese facts show that the main
influencing factors of dust events arc vegetation coverage rate,evaporation, precipitation,rclativc humidity. 'hhe correlation between dust events
and average temperature is not obvious,and average wind speed arc weakly related with it.

Key words: dust events, spatial distribution, metcorolo}ical elements, correlative coefficient, climate

摘要：

利用1951-2000年中国X70个台站沙尘天气和地面气象资料进行了分析，并做了沙尘暴、扬沙、浮尘的空间分布图。分析结果表明沙尘天气主要发生在我国西北、华北地区，有3个多发中心:①以民勤为中心的河西走廊及内蒙占阿拉善高原区;②以和田为中心的南疆盆地南缘区;③以朱日和为中心的内蒙古中部区。另外，以宁夏盐池及内蒙古鄂托克旗为中心的宁、蒙、陕交界处等也是较高的话动区。扬沙、浮尘与沙尘暴的分布很相似。在此基础上，又计算了沙尘天气空间分布与地面气象要索的关系，结果表明:沙尘天气与降水量、相对湿度、植被覆盖率旱显著的负相关，与蒸发量旱正相关。说明影响沙尘天气发生的主要因子是植被覆盖率、蒸发量、降水量和相对湿度。在西北干旱地区，多年平均温度与沙尘天气的发生相关不显著，多年平均风速与沙尘天气的相关也弱.

关键词: 沙尘天气, 空间分布, 气象要索, 相关系数, 气候