Deep critical zone controls on shallow landslides

• 成果类型: Article
• 署名作者: Moon, Seulgi; Formetta, Giuseppe; Higa, Justin T.; Busti, Riccardo; Bellugi, Dino G.; Milledge, David G.; Ebel, Brian A.; Dietrich, William E.
• 署名单位: University of California System; University of California Los Angeles; University of Trento; University of California System; University of California Berkeley; Newcastle University - UK; United States Department of the Interior; United States Geological Survey; University of California System; University of California Berkeley
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.2524542123
• 发表日期: 2026-03-24
• 页码: e2524542123
• 关键词: weathering; critical zone; landslide; natural hazard; hydrology; SURFACE HYDROLOGIC RESPONSE; UNCHANNELED CATCHMENT; WEATHERING PROFILES; rainfall intensity; DURATION CONTROL; COOS-BAY; MODEL; STEEP; FLOW; topography

摘要

The deep critical zone (CZ) has long been recognized for its importance in influencing shallow landslides but was not considered feasible to include in slope stability models at the watershed scale. Here, we demonstrate that simple approximations of the CZ in a fully coupled hydrologic and soil slope stability model can effectively capture the location, timing, and likely size of shallow landslides. To achieve this, we use coupled, process-based models that incorporate the effects of 1) deep CZ structures, 2) three-dimensional transient hydrology, and 3) multidimensional slope stability, calibrated with data from an intensively monitored field site. Our results show that the hydrologically active deep CZ guides groundwater flow, influencing where it drains from or exfiltrates to the soil mantle and producing distinct patterns of soil saturation and seepage forces at the soil-bedrock boundary. A deep conductive, weathered bedrock drains the soil mantle, reducing the likelihood of destabilizing pore pressures, while the downslope thinning of the CZ forces groundwater to the surface. This pattern creates localized instability and a tendency for similar-sized landslides across the landscape. In contrast, the absence of conductive weathered bedrock results in more widespread destabilizing pore pressures, leading to larger landslides and the likelihood of landslides earlier in a storm than in landscapes underlain by a deep CZ. Our findings suggest that first-order variations of deep CZs can provide physical explanations for variations observed in the susceptibility, magnitude, and timing of shallow landslides, and that CZ structure may be inferred from patterns and timing of landsliding.