Grfin Tools – Methods and software for modeling landslide runout and debris-flow growth and inundation
Grfin Tools is a set of software tools that allows users to quickly estimate potential runout from landslides, and (or) inundation from debris flows or lahars, within a DEM. Grfin (pronounced "griffin") is an acronym of Growth + flow + inundation, and the tools within this package apply simple, well-tested, empirical models of runout. This suite of tools can be used individually or in combination to represent a series of linked processes over large areas: from landslide source areas, to unchannelized transport, to channelized flows.
In addition, Grfin Tools can assess inundation from flows that grow volumetrically downstream. This is a vital feature, as volumetric growth commonly results in longer runout distances and larger inundation areas. Grfin Tools can be used for preliminary assessments or as a screening method to identify areas for further detailed study.
The user guide contains information on the basis and methods underlying the tools and models, comprehensive descriptions of the software input and output files, and multiple detailed examples illustrating different applications. The software release contains information on installing and running the package. Users will likely need both documents to successfully run Grfin Tools.
Features and Tools
- Uses empirical models that are computationally efficient and require minimal parameters.
- Assesses potential runout using an empirical height-to-length ratio (angle of reach) method.
- Delineates inundation from different geophysical mass flows, such as debris flows, lahars, and rock avalanches using empirical volume-area relations.
- Evaluates inundation from flows that grow as the travel, using empirical upstream and (or) upslope integrated growth factors to account for growth processes such as channel-bed entrainment, surface erosion, landsliding, and channel-bank failures.
- Distinguishes potential growth zones using various attributes in a topographic curvature-based drainage network.
- Identifies potential sources areas from topography attributes (such as slope), or incorporates user-provided landslide source areas, such as from factor-of-safety slope-stability assessments or mapped landslides.
- Visualize results in any geographical information system (GIS).
Download Links
Grfin Tools user guide and methods
Software install package for Windows OS
ReadMe file for software installation
Full set of examples (large files)
References
If you use Grfin Tools in your work, please cite both of these references:
Reid, M.E., Brien, D.L., Cronkite-Ratcliff, C., and Perkins, J.P., 2025, Grfin Tools—User guide and methods for modeling landslide runout and debris-flow growth and inundation: U.S. Geological Survey Techniques and Methods, book 14, chap. A3, 105 p., https://doi.org/10.3133/tm14A3.
Cronkite-Ratcliff, C., Reid, M.E., Brien, D.L., Perkins, J.P., 2025, Grfin Tools—Software package and runtime documentation for users: U.S. Geological Survey software release, https://doi.org/10.5066/P9NVKFE2.
Grfin Tools is a set of software tools that allows users to quickly estimate potential runout from landslides, and (or) inundation from debris flows or lahars, within a DEM. Grfin (pronounced "griffin") is an acronym of Growth + flow + inundation, and the tools within this package apply simple, well-tested, empirical models of runout. This suite of tools can be used individually or in combination to represent a series of linked processes over large areas: from landslide source areas, to unchannelized transport, to channelized flows.
In addition, Grfin Tools can assess inundation from flows that grow volumetrically downstream. This is a vital feature, as volumetric growth commonly results in longer runout distances and larger inundation areas. Grfin Tools can be used for preliminary assessments or as a screening method to identify areas for further detailed study.
The user guide contains information on the basis and methods underlying the tools and models, comprehensive descriptions of the software input and output files, and multiple detailed examples illustrating different applications. The software release contains information on installing and running the package. Users will likely need both documents to successfully run Grfin Tools.
Features and Tools
- Uses empirical models that are computationally efficient and require minimal parameters.
- Assesses potential runout using an empirical height-to-length ratio (angle of reach) method.
- Delineates inundation from different geophysical mass flows, such as debris flows, lahars, and rock avalanches using empirical volume-area relations.
- Evaluates inundation from flows that grow as the travel, using empirical upstream and (or) upslope integrated growth factors to account for growth processes such as channel-bed entrainment, surface erosion, landsliding, and channel-bank failures.
- Distinguishes potential growth zones using various attributes in a topographic curvature-based drainage network.
- Identifies potential sources areas from topography attributes (such as slope), or incorporates user-provided landslide source areas, such as from factor-of-safety slope-stability assessments or mapped landslides.
- Visualize results in any geographical information system (GIS).
Download Links
Grfin Tools user guide and methods
Software install package for Windows OS
ReadMe file for software installation
Full set of examples (large files)
References
If you use Grfin Tools in your work, please cite both of these references:
Reid, M.E., Brien, D.L., Cronkite-Ratcliff, C., and Perkins, J.P., 2025, Grfin Tools—User guide and methods for modeling landslide runout and debris-flow growth and inundation: U.S. Geological Survey Techniques and Methods, book 14, chap. A3, 105 p., https://doi.org/10.3133/tm14A3.
Cronkite-Ratcliff, C., Reid, M.E., Brien, D.L., Perkins, J.P., 2025, Grfin Tools—Software package and runtime documentation for users: U.S. Geological Survey software release, https://doi.org/10.5066/P9NVKFE2.