中国北方不同区域典型站点降尘特性的对比  

Contrast of Dustfall Characteristics among Different Regions in Northern China

作　　者：李晋昌[1] 董治宝[2] 钱广强[2] 罗万银[2] 

机构地区：[1]山西大学黄土高原研究所,山西太原030006 [2]中国科学院寒区旱区环境与工程研究所沙漠与沙漠化重点实验室,甘肃兰州730000

出　　处：《中国沙漠》2010年第6期1269-1277,共9页Journal of Desert Research

基　　金：中国科学院西部之光博士项目;国家自然科学基金重点项目(40638038)资助

摘　　要：2001年4月—2002年3月,选择位于中国北方沙尘源区的沙坡头和奈曼及位于黄土高原的古县进行了一年的大气降尘监测,并对不同季节降尘量、降尘粒度分布和元素组成进行了系统分析。不同站点大气降尘的这些特性的相同点可能反映了中国北方大气降尘的共性,不同点则反映了沙尘源区与沉降区大气降尘的差异。相同点主要表现为:降尘均主要源于地表沙尘释放,且以地方性颗粒物为主;季节分布均为春季最大、夏季次之、秋季最小;冬半年降尘中远源粉尘含量均大于夏半年,且降尘均主要表现为常态存在的非尘暴降尘。差异性主要表现为:奈曼和古县降尘中人为影响较大;古县降尘受远源影响最大,奈曼次之,沙坡头最小;降尘中粗颗粒物含量以沙坡头最高,古县略低于奈曼;粒度特征的季节变化受风力、源区距离、搬运方式和源区物质组成等因素的共同影响,且具有明显的区域差异。此外,降尘粒度大小与风力并不一定呈正相关,因此,利用黄土粒度来指示冬季风强度时必须结合其他代用指标才能做出较正确的判断。A survey on dustfall was conducted from April 2001to March2002.The dustfall samples were differentially collected from dust source areas（Shapotou and Naiman）and dust deposition area（Guxian）in northern China.Systematic analysis was done from aspects of monthly dustfall amount,dustfall grain size distribution,and element composition.The common characteristics of dustfall in northern China are as follows：Dustfall in each site was generated mainly from local soil surface;Dustfall amount was the most in spring,second in summer,and third in autumn;Remote source contributed more sand in winter half year than it did in summer half year.The regional differences are listed below.Human activities had more contribution to dustfall in Naiman and Guxian,and the contribution of remote sources to dustfall was the highest in Guxian,second in Naiman,and the lowest in Shapotou;The content of coarse particles was the largest in Shapotou,second in Naiman,and the smallest in Guxian;Influenced jointly by wind intensity,land cover of source areas and distance from source area,etc.,the regional differences in seasonal variation of grain size composition were obvious.

关 键 词：降尘 季节变化 沙尘源区 沙尘沉降区 区域差异 

分 类 号：P427.2[天文地球—大气科学及气象学]