img

Wechat

Adv search

Journal of Desert Research ›› 2025, Vol. 45 ›› Issue (1): 44-54.DOI: 10.7522/j.issn.1000-694X.2024.00074

Previous Articles     Next Articles

Study on the grain size characteristics of granule ripplesTaking Dunhuang YardangSanlongsha and Tokexun areas as examples

Kun Zhou1,2(), Qingjie Han1(), Jianjun Qu1, Ruiping Zu1, Bing Liu1   

  1. 1.Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China
    2.University of Chinese Academy of Sciences,Beijing 100049,China
  • Received:2024-04-17 Revised:2024-06-04 Online:2025-01-20 Published:2025-01-13
  • Contact: Qingjie Han

Abstract:

The grain size characteristics are the basis for the study of granule ripple systems and the prerequisite for a deeper understanding of their morphological and developmental processes. In this paper, the grain size characteristics of granule ripple sediments in Dunhuang Yardang, Sanlongsha and Xinjiang Tokexun areas were analysed through large-sample survey and indoor experiments. The results indicate that granule ripples are primarily distributed in four small-scale terrain types: the gobi undulating terrain, yardang corridors, terraces (yardang terrace and foothill denudation terrace), and dune windward slopes. The regularity of crest surface grain size characteristic parameters can be observed. The larger the mean grain size, the greater the degree of separation, the more symmetrical the grain size frequency distribution curve, and the broader and flatter the peaks. In contrast to the previous understanding that the ripple crests were the coarsest and the ripple troughs the finest, the present study indicates that this is not the case. Our findings indicate that the surface grain size reaches its coarsest at the windward slope in close proximity to the crest position, and its finest at the leeward slope in close proximity to the trough position. Furthermore, the grain size characteristics of similar laminae in the mixed layer of the profile is found to be similar, and exhibit a trend whereby the grain size becomes finer with the deepening of the laminae.

Key words: granule ripples, grain size, bimodal distribution, profile stratification

CLC Number: