干旱区生态环境知识资源中心(Arid): 伊犁盆地北部山麓黄土粒度端元指示的粉尘堆积过程

Arid

	伊犁盆地北部山麓黄土粒度端元指示的粉尘堆积过程
其他题名	Dust accumulation processes of piedmont loess indicated by grain-size end members in northern Ili Basin
	李越 1; 宋友桂 2; 宗秀兰 1; 张治平 3; 程良清 1
来源期刊	地理学报
ISSN	0375-5444
出版年	2019
卷号	74 期号:1 页码:162-177
中文摘要	中亚干旱区是全球重要的粉尘源区,是全球变化与区域响应研究的关键区域之一。中亚粉尘形成搬运沉积过程一直是全球变化研究的热点科学问题。本文选取位于伊犁盆地北部、北天山南麓不同地形和气候条件下的两处黄土剖面,对其沉积速率最高的层段进行了粒度测试分析,结合聚类分析和粒度分布曲线拟合两种方法,重建了黄土粉尘的堆积过程。伊犁盆地黄土主要由远源和近源物质组成,分别由高空西风和中尺度的区域风搬运而来。高空西风所携带的远源粘粒级矿物颗粒对盆地东部降雨较高地区有一定的贡献,而在盆地西部不容易沉降下来。中尺度区域风所搬运的近源物质组成了黄土沉积物的主体,而近源区沉积物的可用性在黄土的形成过程中扮演着重要角色。另外,非风暴过程中(沙尘暴过后)出现的浮尘在沙尘暴天气频率减少的时期对黄土的发育有重要贡献,而在沙尘暴天气频发的时期,较差的植被覆盖度能够使得已经沉降下来的浮尘组分重新被扬起至大气中。由此建立了一个粉尘堆积的概念模型。认识黄土粉尘的堆积过程对现代沙尘天气的治理和人类生存环境的改善具有重要作用。
英文摘要	Central Asia, consisting of extended arid and semiarid areas, is one of the major sources of global dust and aerosol in the Northern Hemisphere. Dust emission, transportation and deposition over the region have received an increasing interest. Loess deposits, as a geologic record of dust, enable the possibility of archiving dust variabilities over the past, and give insights into the underlying mechanisms of dust activities. Here, we examined the grain size data of two late Pleistocene loess-paleosol sequences, named Nilka (NLK) and Qingshuihe (QSH), in the Ili Basin, eastern Central Asia, with focus on intervals with the highest sedimentation rates in both loess sections. Both sites are located on the south slope of the northern Tianshan Mountains, but represent different topographies and climate conditions. Parametric curve- fitting and hierarchical cluster analysis techniques were applied to partition the whole spectrum of the measured grain size distributions and provided a more reliable and more representative statistical descriptors. The end members unmixed under distant eolian dynamics were used to reveal the dust accumulation processes in the Ili Basin in detail. The results suggest that the Ili loess mainly consists of distal and proximal sediments, with the highlevel westerlies and the meso-scale regional winds as the transport agents respectively. Distal clayed mineral particles transported by the high- level westerlies can contribute to the loess sediments from the eastern basin due to the wet deposition, where precipitation is high. Nevertheless, this is not true for the western part of the basin where the clay fractions are difficult to deposit. Proximal sediments dominate the Ili loess, and the grain-size composition and formation process of the Ili loess can be dependent on the availability of the local particulate materials with different sizes. Additionally, the floating dust derived from "non-dust storm processes" (after sand and dust storms) has significant impacts on the loess formation during periods of decreasing dust storm frequency. Whereas sparse vegetation is likely to create favorable conditions to the resuspension of the floating dust components when dust storms occur frequently. A conceptual model about dust accumulation in the Ili Basin is proposed based on the above results.
中文关键词	伊犁盆地 ; 黄土 ; 粒度端元分析 ; 粉尘堆积 ; 沙尘天气治理
英文关键词	Ili Basin loess sediments end-member modeling analysis of grain-size distributions dust accumulation control of sand-dust weather
语种	中文
国家	中国
收录类别	CSCD
WOS类目	METEOROLOGY ATMOSPHERIC SCIENCES
WOS研究方向	Meteorology & Atmospheric Sciences
CSCD记录号	CSCD:6424957
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/238999
作者单位	1.中国科学院地球环境研究所;;中国科学院大学, 黄土与第四纪地质国家重点实验室;;, 西安;;, ;;北京 710061;;100049; 2.中国科学院地球环境研究所, 黄土与第四纪地质国家重点实验室, 西安, 陕西 710061, 中国; 3.新疆伊犁哈萨克自治州环境监测站, 伊宁, 835000
推荐引用方式 GB/T 7714	李越,宋友桂,宗秀兰,等. 伊犁盆地北部山麓黄土粒度端元指示的粉尘堆积过程[J],2019,74(1):162-177.
APA	李越,宋友桂,宗秀兰,张治平,&程良清.(2019).伊犁盆地北部山麓黄土粒度端元指示的粉尘堆积过程.地理学报,74(1),162-177.
MLA	李越,et al."伊犁盆地北部山麓黄土粒度端元指示的粉尘堆积过程".地理学报 74.1(2019):162-177.