Transport characteristics of aeolian sand near different thresholds

IF 5.4 1区农林科学 Q1 GEOSCIENCES, MULTIDISCIPLINARY

Catena Pub Date : 2024-11-14 DOI:10.1016/j.catena.2024.108541

Ting Jin , Ping Wang , Bo Cao

{"title":"Transport characteristics of aeolian sand near different thresholds","authors":"Ting Jin , Ping Wang , Bo Cao","doi":"10.1016/j.catena.2024.108541","DOIUrl":null,"url":null,"abstract":"<div><div>The characteristics of wind-blown sand have mainly been derived from steady and continuous sediment transport studies. However, aeolian sand transport exhibits spatiotemporal variability near the threshold, with intermittent transport becoming prominent. This study employs three-dimensional numerical simulations to explore the transport characteristics of wind-blown sand near different thresholds. The results demonstrate varying transport capacities close to the rebound and impact entrainment thresholds, which are 0.38 and 0.7 times the fluid threshold respectively, driven by distinct entrainment mechanisms. Aerodynamic entrainment predominates near the rebound threshold, which shows that the ratio of aerodynamic entrainment particles to splash entrainment particles exceeds 100 with Shields number 0.003. However, splash entrainment becomes dominant when wind velocity surpasses the impact entrainment threshold. The differences in particle energy associated with these entrainment modes alter the transport dynamics of aeolian sand. Understanding these near-threshold behaviors is crucial to comprehensively understanding aeolian processes and accurately mitigating wind erosion hazards.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"247 ","pages":"Article 108541"},"PeriodicalIF":5.4000,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Catena","FirstCategoryId":"97","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0341816224007380","RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"GEOSCIENCES, MULTIDISCIPLINARY","Score":null,"Total":0}

引用次数: 0

Abstract

The characteristics of wind-blown sand have mainly been derived from steady and continuous sediment transport studies. However, aeolian sand transport exhibits spatiotemporal variability near the threshold, with intermittent transport becoming prominent. This study employs three-dimensional numerical simulations to explore the transport characteristics of wind-blown sand near different thresholds. The results demonstrate varying transport capacities close to the rebound and impact entrainment thresholds, which are 0.38 and 0.7 times the fluid threshold respectively, driven by distinct entrainment mechanisms. Aerodynamic entrainment predominates near the rebound threshold, which shows that the ratio of aerodynamic entrainment particles to splash entrainment particles exceeds 100 with Shields number 0.003. However, splash entrainment becomes dominant when wind velocity surpasses the impact entrainment threshold. The differences in particle energy associated with these entrainment modes alter the transport dynamics of aeolian sand. Understanding these near-threshold behaviors is crucial to comprehensively understanding aeolian processes and accurately mitigating wind erosion hazards.

查看原文本刊更多论文

不同临界点附近风化砂的迁移特性

风吹砂的特征主要来自稳定和连续的沉积物运移研究。然而，风吹砂的输运在临界值附近表现出时空变异性，间歇性输运变得突出。本研究采用三维数值模拟来探讨风吹砂在不同临界点附近的输运特征。结果表明，在反弹阈值和冲击夹带阈值（分别为流体阈值的 0.38 倍和 0.7 倍）附近，不同的夹带机制驱动着不同的传输能力。空气动力夹带在反弹阈值附近占主导地位，这表明空气动力夹带颗粒与飞溅夹带颗粒之比超过 100，希尔兹数为 0.003。然而，当风速超过撞击夹带阈值时，飞溅夹带成为主导。与这些夹带模式相关的颗粒能量差异改变了风沙的迁移动力学。了解这些接近阈值的行为对于全面了解风化过程和准确减轻风蚀危害至关重要。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Catena 环境科学-地球科学综合

CiteScore

10.50

自引率

9.70%

发文量

816

审稿时长

54 days

期刊介绍： Catena publishes papers describing original field and laboratory investigations and reviews on geoecology and landscape evolution with emphasis on interdisciplinary aspects of soil science, hydrology and geomorphology. It aims to disseminate new knowledge and foster better understanding of the physical environment, of evolutionary sequences that have resulted in past and current landscapes, and of the natural processes that are likely to determine the fate of our terrestrial environment. Papers within any one of the above topics are welcome provided they are of sufficiently wide interest and relevance.