干旱区研究 ›› 2014, Vol. 31 ›› Issue (4): 636-642.

• 应用气候 • 上一篇    下一篇

新疆艾比湖干涸湖底沉积物粒径分布及其对风蚀的响应

  

  1. (1.中国科学院新疆生态与地理研究所,荒漠与绿洲生态国家重点实验室,新疆 乌鲁木齐 830011; 2.中国科学院大学,北京 100049)
  • 收稿日期:2013-04-25 修回日期:2014-01-19 出版日期:2014-07-15 发布日期:2014-08-11
  • 作者简介:葛拥晓(1987-),博士研究生,主要从事环境演变和景观地球化学研究.E-mail: yongxiao-ge@hotmail.com
  • 基金资助:

    国家自然科学基金项目(41071139);中国科学院“西部之光”人才培养计划西部博士项目(XBBS201106);中国科学院知识创新工程重要方向性项目(KZCX2-EW-308)

Response of Granularity Distribution to Wind Erosion in the Playa of the Ebinur Lake, Xinjiang, Northwest China

  • Received:2013-04-25 Revised:2014-01-19 Online:2014-07-15 Published:2014-08-11

摘要: 艾比湖已经干涸的湖底常年经历强烈风蚀,形成危害较大的沙(盐)尘暴。为了解风蚀过程干涸湖底沉积物粒径分布的变化特征,在干涸湖底选择无植被覆盖(S1)、芦苇荒漠带(S2)、梭梭荒漠带(S3)3个区域作为研究区,运用粒径分布参数表征粒径分布特征对风蚀的响应。结果表明:① 由于不同区域沉积物形成时间差异,S1、S2、S3之间粒级组成、平均粒径均差异显著。S1的沉积物为黏粒—粉粒—极细砂类型,其中,粉粒含量最高,为80.60%,相比其他两个区含量较大,但是平均粒径最小,在6.10Φ~6.30Φ之间;S2为粉粒—细砂—中砂类型,砂粒含量最高为87.71%,质地较粗变化幅度较大,平均粒径在2.25Φ~3.54Φ;而S3为粉粒—极细砂—细砂—中砂类型,各粒级含量相对比较平均,不同深度含量差别较大,平均粒径在3.38Φ~5.65Φ。② 干涸湖底不同区域沉积物粒级含量、粒径分布参数对风蚀的响应特征不同。由于风蚀程度不同,S1和S2 0~10 cm的沉积物,无覆盖区域和覆盖区域平均粒径、粒级含量差异显著,且随深度的增加,差异显著性呈现降低趋势。S3无覆盖和覆盖区域的平均粒径、粒级含量差异均不明显。

Abstract: Wind erosion, especially in arid zone, is one of the basic geomorphologic processes that shapes different landscapes. The playa of the Ebinur Lake suffers from strong wind erosion, which may cause the occurrence of harmful sand (salt) storms. In order to understand the variation of granular distribution in the playa of the Ebinur Lake, the granular distribution parameters were used to characterize the response of granular distribution to wind erosion in the selected three regions in a bare desert including S1, S2 and S3, where [WTBX]Phragmites australis, Haloxylon ammodendron[WTBZ] and [WTBX]Halocnemum strobilaceum[WTBZ] are the dominant species. The results showed that the fraction content at the same soil depth was significantly different from the different sample sites due to the different time of the formation of deposits in different regions. Generally speaking, the study area S1 was mainly consisted of clay, silt and very fine sand, and the silt content was as high as 80.60%. In the study area S2, the sand content was as high as 87.71%, and the average particle size ranged from 2.25Φ to 3.54Φ. However, the study area S3 was consisted of silt, very fine sand, fine sand and midsized sand, and the average particle size varied from 3.38Φ to 5.65Φ. The response of fraction content and granular parameters of sediment from the three typical regions to wind erosion was different. The average particle sizes (0-10 cm) and granular distribution of sediment in the covered area were significantly different from that in the area without cover. Moreover, such difference was reduced with the increase of soil depth.