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中国沙漠 ›› 2019, Vol. 39 ›› Issue (2): 202-208.DOI: 10.7522/j.issn.1000-694X.2019.00012

• • 上一篇    

戈壁沙砾质地表沉积物全粒径分布模式及其对分选作用的指示意义

熊鑫1, 王海兵1, 肖建华2, 左合君1   

  1. 1. 内蒙古农业大学 沙漠治理学院/内蒙古风沙物理与防沙治沙工程重点实验室, 内蒙古 呼和浩特 010011;
    2. 中国科学院西北生态环境资源研究院, 甘肃 兰州 730000
  • 收稿日期:2018-09-26 修回日期:2019-01-20 发布日期:2019-04-11
  • 通讯作者: 王海兵(E-mail:hbwang@imau.edu.cn)
  • 作者简介:熊鑫(1995-),女,内蒙古鄂尔多斯人,硕士研究生,主要从事水土保持与荒漠化防治研究。E-mail:xiongxin0126@126.com
  • 基金资助:
    国家自然科学基金项目(41861001);内蒙古自治区研究生教育创新计划资助项目(S2018111989Z)

Particle Size Distribution Models of Gobi Sediments and Its Significance to the Effect of Sorting

Xiong Xin1, Wang Haibin1, Xiao Jianhua2, Zuo Hejun1   

  1. 1. Desert Science and Engineering College/Key Laboratory of Aeolian Sand Physics and Sand Control Engineering in Inner Mongolia, Inner Mongolia Agricultural University, Hohhot 010011, China;
    2. Northwest Institute of Eco-Environmental and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
  • Received:2018-09-26 Revised:2019-01-20 Published:2019-04-11

摘要: 戈壁地表沉积物组分呈多峰态分布的特征,研究其全粒径分布模式是认识戈壁成因及形成过程的基础。目前粒度分布模式(对数正态分布、Weibull分布等)难以正确表达呈多峰态的沉积物粒度分布特征,本文利用单调递减函数Pdi)=Cdi-μexp(-di/Dc),对戈壁地表沉积物粒度的全粒径分布模式进行解析。结果表明:(1)该函数能够反映出戈壁地表沉积物组分的全粒径分布特征,拟合优度R2>0.99,参数C值范围为52.64~166.75,μ为-0.083~0.108,Dc为0.103~2.336;(2)在分选作用下,以富沙组分为主的戈壁地表,跃移组分含量高,μ值、Dc值偏小,以富砾组分为主的戈壁地表,蠕移及风蚀残余组分含量高,μ值、Dc值偏大;(3)全粒径分布模式参数值可以揭示洪积扇戈壁的分选沉积特征,为解析戈壁地表的成因以及风蚀风积作用提供新的指标参数。

关键词: 粒度组分, 全粒径分布模式, 沙砾质地表, 戈壁

Abstract: Studying particle size distribution models is the basis for understanding the formation process of gobi. However, the frequency distribution of surface sediment components in gobi desert are characterized by multimodal, and the general particle size distribution function with Log-normal or Weibull distribution are difficult to be used to correctly express the particle size distribution characteristics of sediments with multimodal. Therefore, this study was designed to analyze the particle size distribution of the gobi surface sediments using the monotonicaly decreasing function P(di)=Cdi-μexp(-di/Dc). The results showed that this function was able to reflect the particle size distribution characteristics of gobi surface sediment components with the goodness of fit as R2>0.99. The range of parameter C was 52.64-166.75, μ was 0.083-0.108, and Dc was 0.103-2.336. Under the effect of sorting, the components for jumping movement was large with relatively small μ and Dc values in sand-rich surface of gobi. The residual components for wind-induced erosion and creep movement was large with relatively large μ and Dc values in gravel-rich surface of gobi. The parameters using particle size model can reveal the sorting sedimentary characteristics of alluvial fan gobi and provide a new indicating parameter for analyzing the formation process of gobi surface and the wind-induced erosion.

Key words: particle size components, particle size distribution model, sandy gravelly surface, gobi

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