watershed_size: A polygon shapefile outlining watershed areas used for debris flow runout simulations. These polygons represent debris contribution areas in modeled simulations. landslide_inventory: Feature class containing polygons outlining the extent of landslide deposits identified in the 2018 high-resolution lidar data. scenario1_modeled_debris_flow_runout: Raster image data depicting the modeled extent of debris flow runout zones simulated using LaharZ (Iverson and others, 1988; Schilling, 1998). Volumes for runout zone modeling were estimated based on known debris flows; the 2014 Starrigavan debris flow [(high volume; 11,000m3 (388,461ft3)], 2015 South Kramer debris flow [(medium volume; volume; 48,000m3 (1,695104ft3)], and 2015 Silver Baby debris flow [(low volume; 9,000m3 (31783 ft3)]. In this scenario debris flow runout is modeled using the best fitting parameters calibrated on the South Kramer debris flow. scenario2_modeled_debris_flow_runout: Raster image data depicting the modeled extent of debris flow runout zones simulated using LaharZ (Iverson and others, 1988; Schilling, 1998). Volumes for runout zone modeling were estimated based on known debris flows; the 2014 Starrigavan debris flow [(high volume; 48,000m3 (388,461ft3)], 2015 South Kramer debris flow [(medium volume; volume; 11,000m3 (1,695104ft3)], and 2015 Silver Baby debris flow [(low volume; 9,000m3 (31783 ft3)]. In this scenario debris flow runout is modeled using the best fitting parameters calibrated on the North Kramer debris flow. slope_susceptibility: Raster image data model of the relationship between shear forces acting to move material downslope and forces acting to resist downslope movement. This is a representation of the Factor of Safety (FOS).
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We want to thank Jacqueline Foss from the U.S. Forest Service for her helpful discussions about the data and the time she spent sharing her knowledge of debris flows in Southeast Alaska. We appreciate Brinnen Carter from the Sitka National Historical Park for his help with logistics and insights about debris flows in Sitka. Staff with the City and Borough of Sitka were extremely helpful in tracking down data and providing important input. We wish to acknowledge Cynthia McCoy from FEMA for her guidance during the completion of the project, as well as Dennis Staley at the USGS and Bill Burns at DOGAMI for reviews that helped to improve the quality of this product. We also thank Patricia Ekberg and Amy Macpherson for GIS and cartographic support. This project was funded by the FEMA Cooperating Technical Partners Program (grant number EMS-2016-CA-00006). Lidar data collection was partially funded by a Cooperative Agreement between the National Park Service and DGGS (grant number P17AC00903).
This study provides a regional evaluation of debris flow hazards in and around Sitka. The study aims to help the community better understand debris flow hazards, inform mitigation efforts, guide future development activities, and protect public safety.
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Are there legal restrictions on access or use of the data?Access_Constraints:
This report, map, and/or dataset is available directly from the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys (see contact information below).Use_Constraints:Any hard copies or published datasets utilizing these datasets shall clearly indicate their source. If the user has modified the data in any way, the user is obligated to describe the types of modifications the user has made. The user specifically agrees not to misrepresent these datasets, nor to imply that changes made by the user were approved by the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys. The State of Alaska makes no express or implied warranties (including warranties for merchantability and fitness) with respect to the character, functions, or capabilities of the electronic data or products or their appropriateness for any user's purposes. In no event will the State of Alaska be liable for any incidental, indirect, special, consequential, or other damages suffered by the user or any other person or entity whether from the use of the electronic services or products or any failure thereof or otherwise. In no event will the State of Alaska's liability to the Requestor or anyone else exceed the fee paid for the electronic service or product.
The State of Alaska makes no expressed or implied warranties (including warranties for merchantability and fitness) with respect to the character, functions, or capabilities of the electronic data or products or their appropriateness for any user's purposes. In no event will the State of Alaska be liable for any incidental, indirect, special, consequential, or other damages suffered by the user or any other person or entity whether from the use of the electronic services or products or any failure thereof or otherwise. In no event will the State of Alaska's liability to the Requestor or anyone else exceed the fee paid for the electronic service or product.
| Data format: | digital data in format shapefile, raster |
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| Network links: |
https://doi.org/10.14509/30187 |