Investigations on the initiation mechanism of rainfall-induced loess landslides driven by sinkhole-assisted seepage: a case study in Qinghai, China
4 affiliations
- 1Qinghai Geological Survey Institute
- 2Badong National Observation and Research Station of Geohazards, China University of Geosciences
- 3East China Electric Power Design Institute Co., Ltd. of China Power Engineering Consulting Group
- 4China Railway Bridge Science Research Institute Co., Ltd.
Abstract
On 4 September 2024, a sudden loess landslide occurred in Henagou Village, Qinghai Province, China, after 19 h of rainfall (44.9 mm), causing three fatalities and one injury. Field investigation revealed that pre-existing sinkholes and their connected subsurface seepage pathways played a key role in slope failure. Rainwater was preferentially captured by sinkholes and rapidly conveyed toward the weak band, where wetting-induced softening and pore-water-pressure increase significantly reduced slope stability. To clarify this process, we combined field surveys, double-ring infiltration tests, laboratory shear tests, and FLAC3D hydro-mechanical simulations. The results show that sinkholes acted as efficient preferential-flow conduits, accelerating infiltration and promoting localized pore-pressure build-up along the weak band. This led to concentrated shear-strain development and rapid displacement growth, with the simulated initiation time reaching 18.8 h after the onset of rainfall. Comparative simulations further indicate that sinkhole-assisted seepage substantially shortened the pre-failure period relative to the case without sinkholes. The study highlights the critical role of sinkhole-controlled preferential seepage in rainfall-induced loess landslides and provides a useful basis for hazard recognition and risk assessment in similar loess regions.
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BibTeX
@article{cai2026investigations,
title = {{Investigations on the initiation mechanism of rainfall-induced loess landslides driven by sinkhole-assisted seepage: a case study in Qinghai, China}},
author = {Shengshun Cai and Xuan Liu and Ruyi Wang and Qinwen Tan and Mengshuang Huang and Meng Zhao and Shandong Bao and Yanzhe Li and Linhu Wu},
journal = {Scientific Reports},
year = {2026},
month = jul,
doi = {10.1038/s41598-026-63102-0},
url = {https://doi.org/10.1038/s41598-026-63102-0},
note = {CC BY},
}
RIS
TY - JOUR
TI - Investigations on the initiation mechanism of rainfall-induced loess landslides driven by sinkhole-assisted seepage: a case study in Qinghai, China
AU - Shengshun Cai
AU - Xuan Liu
AU - Ruyi Wang
AU - Qinwen Tan
AU - Mengshuang Huang
AU - Meng Zhao
AU - Shandong Bao
AU - Yanzhe Li
AU - Linhu Wu
PY - 2026
DA - 2026/07/01
JO - Scientific Reports
DO - 10.1038/s41598-026-63102-0
UR - https://doi.org/10.1038/s41598-026-63102-0
AB - On 4 September 2024, a sudden loess landslide occurred in Henagou Village, Qinghai Province, China, after 19 h of rainfall (44.9 mm), causing three fatalities and one injury. Field investigation revealed that pre-existing sinkholes and their connected subsurface seepage pathways played a key role in slope failure. Rainwater was preferentially captured by sinkholes and rapidly conveyed toward the weak band, where wetting-induced softening and pore-water-pressure increase significantly reduced slope stability. To clarify this process, we combined field surveys, double-ring infiltration tests, laboratory shear tests, and FLAC3D hydro-mechanical simulations. The results show that sinkholes acted as efficient preferential-flow conduits, accelerating infiltration and promoting localized pore-pressure build-up along the weak band. This led to concentrated shear-strain development and rapid displacement growth, with the simulated initiation time reaching 18.8 h after the onset of rainfall. Comparative simulations further indicate that sinkhole-assisted seepage substantially shortened the pre-failure period relative to the case without sinkholes. The study highlights the critical role of sinkhole-controlled preferential seepage in rainfall-induced loess landslides and provides a useful basis for hazard recognition and risk assessment in similar loess regions.
SN - 2045-2322
ER -