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Abstract During December 2022–January 2023, nine atmospheric rivers (ARs) struck California consecutively, causing catastrophic flooding and 600+ landslides. The extensive footprints of landslide‐triggering storms and their diverse hydrometeorological forcings highlight the urgent need to incorporate regional‐scale hydrometeorology into landslide research. Here, using a meteorologically‐informed hydrologic model, we simulate the time‐evolving water budget during the nine‐AR event and identify hydrometeorological conditions that contributed to widespread landslide occurrences across California. Our analysis reveals that 89% of observed landslides occurred under excessively wet conditions, driven by precipitation exceeding the capacities of infiltration, storage, evapotranspiration, and soil drainage. Using K‐means clustering, we identify three distinct hydrometeorological pathways that increased landslide potential: intense precipitation‐induced runoff (∼32% of reported landslides), rain on pre‐wetted soils (∼53%), and snowmelt and soil ice thawing (∼15%). Our findings highlight the importance of constraining the compounding factors that influence slope stability over spatial scales consistent with landslide‐triggering weather systems.
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Evaluating Transient Drawdown and Slope Stabilization from Horizontal Drain Installation
Elevated groundwater levels drive slope instability through decreased effective stresses and frictional strength. Consequently, landslide mitigation often relies on a variety of stabilizing techniques, often including dewatering and drainage as a primary control on stability. One of the most effective dewatering techniques for landslides are horizontal drain systems, which consist of arrays of perforated pipes drilled into hillslopes for gravity-driven removal of groundwater. One of the few economical solutions for large-magnitude, groundwater-driven landslides, horizontal drain arrays facilitate groundwater drawdown through gravity-driven flow, consequently increasing effective stress and slope stability within its domain of influence. However, design of horizontal drain systems remain largely observational and there is limited insight towards the transient performance of these drainage systems. This study aims to explore relevant theoretical design criteria for horizontal drain systems and their relative importance as related to drawdown mechanism and magnitude, as well as slope stability.
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- Award ID(s):
- 2050047
- PAR ID:
- 10553608
- Publisher / Repository:
- Elsevier Ltd.
- Date Published:
- Journal Name:
- Computers and Geotechnics
- Volume:
- 167
- Issue:
- C
- ISSN:
- 0266-352X
- Page Range / eLocation ID:
- 106044
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1016/j.compgeo.2023.106044
