Project Timeline:
January 1, 2020 - December 31, 2026
CMER Scientist:
Elise Freeman
Principal Investigator:
Elise Freeman
Project Manager:
Theryn Henkel
Rule Group:
Unstable Slopes
SAG:
UPSAG (Upslope Processes Science Advisory Group)
In Washington State, deep-seated landslides (DSLs) occur within many lithologies and across wide breadths of climate regimes and timescales. These differences in geologic materials, climates and timescales suggest that different geographies are more or less sensitive to contemporary natural and anthropogenic landslide triggering mechanisms. Of particular interest to the Adaptive Management Program are the potential effects of hydrologic inputs from forest management on different classes of DSLs, especially where landslides have the potential to degrade fish habitat and water quality or threaten public safety. Increases in groundwater recharge due to decreases in evapotranspiration from timber harvest may impact DSL processes. However, few guidelines are available to determine if an individual DSL will respond to harvest-induced changes in hydrology. Developing a DSL classification system that is based on specific factors, such as material properties, geomorphic setting and hydrology, will provide the framework for designing the subsequent, empirical research projects in the DSL Strategy. These projects will address the geologic hazards and evaluate hydrologic sensitivities due to timber harvest relative to other triggers.
This project, Landslide Mapping and Classification, is intended to provide a classification of DSLs inferred to represent a range of potential landslide susceptibility to natural and forest practice triggers. The project aims to empirically define classes of DSLs based on critical independent variables that control the occurrence and type of failure. These critical independent variables include, but may not be limited to, hydrology, lithology, stratigraphy, and topographic setting. This effort will provide the framework needed to pursue the subsequent projects in the Strategy which are designed to specifically investigate landslide mechanics and hydrology based on the landslide classification.
Traditionally, geotechnical investigations and academic research on DSLs are done at the scale of individual landslides. These investigations are conducted in the context of construction projects, such as the building or repair of a segment of highway and academic research focused on specific failure mechanisms, as well as in the context of forest practices. Broad classifications of landslide type, typically based on geologic materials and movement mechanisms, are the standard. However, a classification schema that can be applied to DSLs in the context of forest practices-associated hazards and risk does not exist. An exploratory approach is appropriate for developing the methods needed to address this gap in our understanding. Considering the breadth of Washington State and the specific focus of forest practices rules on hundreds of DSLs, there is an imperative to create an effective classification system based on sound geologic principles.
Project Manager
Principal Investigator, NWIFC
Project Team Member, Rayonier Inc.
Project Team Member, DNR
Project Team Member, Conservation Caucus
Project Team Member, Weyerhaeuser
Project Team Member, Nooksack Tribe
No documents associated with this phase.
No documents associated with this phase.
No documents associated with this phase.
