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干旱区地理 ›› 2021, Vol. 44 ›› Issue (2): 379-388.doi: 10.12118/j.issn.1000–6060.2021.02.09

• 地表过程研究 • 上一篇    下一篇

中国西部河谷型城市土壤与灰尘粒级组分分布特征

高瑜1,2(),李小平1,2(),张钰超1,2,曹瑜函1,2,李涛1,2,杨涛1,2,王利军1,2   

  1. 1.陕西师范大学环境科学系,陕西 西安 710062
    2.陕西省污染暴露与生态环境健康国际联合研究中心,陕西 西安 710062
  • 收稿日期:2019-12-15 修回日期:2021-01-18 出版日期:2021-03-25 发布日期:2021-04-14
  • 通讯作者: 李小平
  • 作者简介:高瑜(1994-),男,博士研究生,研究方向为生态环境评价与修复. E-mail:gaoyu1911@snnu.edu.cn
  • 基金资助:
    国家自然科学基金项目(41877517);国家自然科学基金项目(41471420);国家自然科学基金项目(41877516);陕西省科技创新基地项目(2018GHJD-16);中央高校基本科研业务费重点项目资助(GK202102007)

Spatial distribution of particle fractionations of dust and soil in the valley-city of northwest China

GAO Yu1,2(),LI Xiaoping1,2(),ZHANG Yuchao1,2,CAO Yuhan1,2,LI Tao1,2,YANG Tao1,2,WANG Lijun1,2   

  1. 1. Department of Environment Sciences, Shaanxi Normal University, Xi’an 710062, Shaanxi, China
    2. International Joint Research Center of Shaanxi Province for Pollution Exposure and Ecoenvironment Health,Xi’an 710062, Shaanxi, China
  • Received:2019-12-15 Revised:2021-01-18 Online:2021-03-25 Published:2021-04-14
  • Contact: Xiaoping LI

摘要:

通过采集兰州市和延安市主城区的土壤灰尘样品,测量了其粒径组成,界定了土壤和灰尘不同粒径的空间分布,分析了环境影响。结果表明:兰州市和延安市城市土壤灰尘粒径组成有明显的分布特征,主要集中在小于100βμm的部分,整体粒径分布情况为:粉黏粒(<50βμm)>极细砂(50~100βμm)>细砂(100~250βμm)>中砂(250~500βμm)>粗砂(500~1000βμm)。其中兰州市小于100βμm灰尘颗粒物粒径所占比例(69.17%)大于延安市(53.49%),极易在外动力条件下再次扬起成为扬尘污染的潜在污染源。从2个城市土壤和灰尘<PM10粒径组分空间分布特征来看,同粒度的上风向城市土壤是同粒度下风向的城市灰尘的潜在来源,工业活动对土壤小粒径组分的影响可能更大,频繁的人类活动对灰尘小粒径组分的影响可能更大。

关键词: 土壤灰尘, 粒径分布, 环境效应, 兰州市, 延安市

Abstract:

Both Lanzhou and Yan’an are valley cities in northwest China that are critical for the petrochemical industry and energy and have frequent dusty weather. The fine particles and dust in the soil easily enter the atmosphere and cause haze pollution. However, basic data, such as urban soil characteristics and dust particle size in this area are lacking. This study collected soil and dust samples in the main urban area of Lanzhou and Yan’an. The particle size composition was measured using a laser particle size analyzer. The environmental effects were analyzed through spatial distribution and particle size of soil and dust. We provide scientific data and a theoretical basis for the urban environmental protection in Lanzhou and Yan’an. The results show that the principal size fractions of soil and dust in Lanzhou and Yan’an were no more than 100 μm. The overall grain size distribution trend decreased as silty clay (<50 μm) > impalpable sand (50-100 μm) > fine sand (100-250 μm) > medium sand (250-500 μm) > coarse medium sand (500-1000 μm). The proportion of dust particle size less than 100 μm in Lanzhou is 69.17%, which was larger than in Yan’an (53.49%). The results indicate that the fractionation in dust of less than 100 μm was easy to increase under an external power condition and become the potential source of pollution and human health risk. The results of spatial distributions of PM1, PM2.5, and PM10 in soil and dust showed that the same size of urban soil in the upper wind direction was a source of urban dust under the same size wind direction. Furthermore, industrial activities significantly influence small-sized soils, and frequent human activities significantly influence small-sized dust. Correlation analysis was conducted using Spass 21 software on a proportion of different particle levels between soil dust in Lanzhou and Yan’an, respectively. A significant correlation exists between different soil and dust particle levels in Lanzhou, with a correlation coefficient of r=0.967, which is a strong correlation. A significant correlation also exists between soil and dust in Yan’an, with r=0.767, indicating that soil fine particles might partly contribute to dust.

Key words: soil and dust, particle size distribution, environment effect, Lanzhou City, Yan’an City