A hybrid mechanism for the initiation and expansion of loess caves across the Chinese Loess Plateau

Author:

Geng Haopeng12ORCID,Xu Wanying1ORCID,Zheng Weishan1,Gao Xiaolei1,Pan Baotian12

Affiliation:

1. Key Laboratory of Western China's Environmental Systems (Ministry of Education), College of Earth and Environmental Sciences Lanzhou University Lanzhou 730000 PR China

2. Shiyang River Basin Scientific Observing Station of Gansu Province Lanzhou PR China

Abstract

AbstractLoess caves are a distinctive and widespread landform on the Chinese Loess Plateau (CLP). Their formation contributes considerably to the soil erosion and land degradation; however, quantitative studies that improve the mechanistic understanding of their formation are still lacking. We aimed to explore the formation mechanism of loess caves and selected nine study sites across the CLP with different degrees of cave development and varied environmental conditions. We surveyed the study sites (~9.6 km2) using an unmanned aerial vehicle (UAV). We mapped the loess caves using high‐resolution UAV images and quantified their degree of development (i.e., density and area). We then analyzed the topographic characteristics of loess caves at individual sites and examined the environmental controls (i.e., climatic factors and soil properties) on the degree of loess cave development at different sites. The results show that loess caves are predominantly distributed in gullies and high topographic wetness index areas with clear topographic preferences, which suggests that cave initiation is accomplished by mechanical scouring. The average area correlated negatively with density but positively with saturated hydraulic conductivity, indicating loess cave expansion is a dissolution process caused by infiltrated water. Finally, we proposed a hybrid mechanism for loess cave development, where mechanical scouring dominates the initiation and dissolution expansion drives their expansion. Both initiation and expansion need, but compete for, surface runoff, and hydrologically relevant processes dominate loess cave development. Based on the non‐linear relationship between loess cave development and precipitation (NDVI), we proposed that the impact of vegetation rehabilitation on loess cave development needs to be assessed on a sub‐regional basis.

Funder

National Natural Science Foundation of China

Publisher

Wiley

Subject

Soil Science,General Environmental Science,Development,Environmental Chemistry

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3