2021年“3·15”沙尘暴沙尘来源核素示踪研究  

Use of radionuclides to trace sand and dust sources of the March 15,2021 dust storm event

作　　者：史忠林[1] 张信宝[1] 张润川 Shi Zhonglin;Zhang Xinbao;Zhang Runchuan(CAS Key Laboratory of Mountain Surface Processes and Ecological Regulation,Institute of Mountain Hazards and Envi‐ronment,Chinese Academy of Sciences,Chengdu 610041,China)

机构地区：[1]中国科学院、水利部成都山地灾害与环境研究所中国科学院山地表生过程与生态调控重点实验室,四川成都610041

出　　处：《中国沙漠》2022年第2期1-5,共5页Journal of Desert Research

基　　金：中国科学院“西部青年学者”项目;国家自然科学基金项目(41873025)。

摘　　要：沙尘暴对大气环境和人类健康造成严重影响,查明沙尘来源对防沙治沙具有重要意义。选择中国北方7地2021年“3·15”沙尘暴期间降尘样品,分析粒度组成和核素(^(235)U、^(232)Th、^(226)Ra、^(137)Cs)含量差异。结果表明:西宁、兰州、西安、北京、济南和临沂6地降尘以粉粒为主,核素含量特征表明降尘是远距离搬运的风尘沉积或吹蚀起的附近黄土。除中卫和西安外,其余5地沙尘的^(137)Cs比活度远高于农耕地,低于植被覆盖度高的草地,沙尘的主要来源应不是农耕地,而是覆盖度低的侵蚀草地。西安沙尘的^(137)Cs比活度与农耕地相近,农耕地可能是沙尘的主要来源。中卫沙尘粒度粗,^(137)Cs比活度极低,沙尘来源于毗邻的腾格里沙漠。Dust storms have serious impacts on the atmosphere and human health.It is,therefore,of great significance to identify the sources of sand and dust for preventing and controlling such storms.In this study,sand-dust samples were collected from seven points in northern China during the dust storm event on March 15,2021,and their particle size composition and some radionuclide(^(235)U,^(232)Th,^(226)Ra and ^(137)Cs)concentrations were measured.Results show that the sand-dust samples of Xining,Lanzhou,Xi'an,Beijing,Ji'nan and Linyi were dominated by silt particles.Radionuclide content characteristics indicate that these dust were long-distance transported Aeolian dust or blown loess nearby.Except for Zhongwei and Xi'an,^(137)Cs activities of the sand-dust in the other five locations were much higher than that of cultivated land and lower than that of grassland with high vegetation coverage,indicating that they were mainly originated from eroded grasslands with low coverage rather than cultivated lands.The ^(137)Cs activity of the sand-dust of Xi'an was similar to that of the cultivated lands,means that these lands may be the dominate source of the sand and dust.The Zhongwei sample was coarse in grain size and extremely low in ^(137)Cs activity,because it was originated from the adjacent Tengger Desert.

关 键 词：沙尘暴 来源 放射性核素 示踪 ^(137)Cs 

分 类 号：P445.4[天文地球—大气科学及气象学]