【摘要】 利用1951~2000年中国470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古阿拉善高原区;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活动区。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素的关系,结果表明:沙尘天气与降水量、相对湿度、植被覆盖率呈显著的负相关,与蒸发量呈正相关。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。更多还原

【Abstract】 Based on the surface meteorological observation data and dust event days from 470 stations in China from 1951 to 2000,the spatial distribution of dust storm,sand blowing,dust in January,April,July,October in Northern China has been analyzed.The results show that the dust events originate mainly from both the Northwest and the North of China,there are three regions where the dust events occur frequently,which are Hexi corridor and Alashan plateau with the center of Mingqin county;the southern edge of Tarim basin with the center of Hetian;the middle part of Inner Mongolia with the center of Zhurihe.In addition,there is another region with the center of both Ningxia Yanchi and Etuoke area of Inner Mongolia,where dust storm occurred frequently too.The spatial distributions of dust storm,sand blowing,dust are basically coincident.Then,according to surface meteorological data,the relations between dust events distribution and surface meteorological elements have been studied in this paper. The results are as follows:the correlations between dust events and precipitation,relative humidity as well as vegetation coverage rate are obviously negative,and the correlation between dust events and evaporation is positive.These facts show that the main influencing factors of dust events are vegetation coverage rate,evaporation,precipitation,relative humidity.The correlation between dust events and average temperature is not obvious,and average wind speed are weakly related with it.更多还原