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中国沙漠 ›› 1997, Vol. 17 ›› Issue (2): 112-118.

• 研究论文 • 上一篇    下一篇

金字塔沙丘形成的动力条件分析

凌裕泉1, 刘绍中2, 吴正3, 李长治1   

  1. 1. 中国科学院兰州沙漠研究所, 兰州 730000;
    2. 中国科学院成都计算机应用研究所, 成都 610041;
    3. 华南师范大学地理系, 广州 510631
  • 收稿日期:1996-11-11 出版日期:1997-06-20 发布日期:1997-06-20
  • 作者简介:凌裕泉,男,1935年生,研究员。多年来主要从事风沙物理与风沙工程研究。
  • 基金资助:
    国家自然科学基金资助项目(49371009)的系列研究成果之一

ANALYSIS ON DYNAMICS CONDITIONS OF PYRAMID DUNES FORMATION

Ling Yuquan1, Liu Shaozhong2, Wu Zheng3, Li Changzhi1   

  1. 1. Institute of Desert Research, Chinese Academy of Sciences, Lanzhou 730000;
    2. Institute of Computer Application, Chinese Academy of Sciences, Chengdu 610041;
    3. Geography Department of Sou th China Normal University, Guangzhou, 510631
  • Received:1996-11-11 Online:1997-06-20 Published:1997-06-20

摘要: 金字塔沙丘(或星状沙丘)形成的动力条件主要有三个方面:一是在非沙质床面的气流场辐合区,一般具有三个以上近似均布的主风向,各主风向的风力强度、出现频率及持续时间不尽相同,但年总输沙能力较为接近,而且月输沙能力具有明显的季节变化;二是不太充裕的沙源和高浓度不饱和风沙流;三是不同尺度地形条件的动力作用,和沙漠与戈壁下垫面的热力影响。在沙质床面,往往由于高浓度饱和或过饱和风沙流的作用,导致新月形沙丘或新月形沙丘链的变态,或重新组合成金字塔状的沙丘形态,但不可能发育为典型的金字塔沙丘。

关键词: 金字塔沙丘, 高浓度风沙流, 气流场辐合区

Abstract: The dynamics conditions of pyramid dunes(or star dunes) formation have three respects.First the flow convergent field on the non-sandy bed possess:1) over three dominant wind directions which are approximately uniform distribution,2) their intensity and frequency and sustained time in each time are different,3) their total sand transported quantity in a year is similar,and 4) monthly sand transported quantity has obvious seasonal changes.Second,none abundant sand source and the wind-sand flow with high sand transported quantity and less accumulation.Third,the dynamics action of different scale topography,and the heating power influence on desert and Gobi under-layer.On the sandy bed,the high concentration saturated wind-sand flow or oversaturated wind-sand flow often lead to the abnormal status of barchan dunes and barchan dune chains,or re-build new pyramid like sand dunes which cannot be developed into the typical pyramid dunes.

Key words: Pyramid dunes, High concentration wind-sand flow, Flow convergent field

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