{ "culture": "en-US", "name": "", "guid": "", "catalogPath": "", "snippet": "These data were produced to provide attribute and spatial information on landslides in Washington State. This data is non-regulatory and is intended for informational purposes. It may not be suitable for legal, engineering, forestry, or surveying purposes; but it is intended to assist planners, homeowners, regulators, and others by identifying areas to seek further geologic investigation in before developing, or areas to avoid. Users of this information should consider their intended application, and review or consult the accompanying documentation, to determine the usability of the data for themselves.", "description": "

This feature class contains landslides compiled from a variety of sources, spanning the past few decades. The Landslide Compilation contains landslides from the following sources: (1) Landslides that are mapped within 1:24,000-scale geologic mapping (not statewide) and our statewide 1:100,000-scale geologic map compilation; (2) a miscellaneous compilation of pre-existing landslide data from several sources, including the Washington Geological Survey, the Department of Natural Resources\u2019 Forest Practices Division, and other federal and private entities; (3) landslides mapped as part of Watershed Analysis efforts for the Forest Practices Board; (4) reconnaissance-scale mapping of landslides associated with significant landslide events; and (5) a study of near-shore landforms along the Salish Sea.<\/SPAN><\/P>

1:24,000-scale and 1:100,000-scale Landslides from Geologic Mappings how landslides that were extracted from 1:24,000- and 1:100,000-scale geologic maps. Landslide mapping was not the primary purpose of these projects, and the absence of a mapped landslide in a particular location does not suggest that no landslide exists or that there is no landslide risk. Also, due to the scale of the final mapping products, landslides with deposits too small to be identified in any included scale of geologic mapping (for example, debris flows, debris avalanches, rock topples, etc.) are not typically included. Only partial coverage exists for landslides mapped at 1:24,000 scale. 1:100,000-scale mapping covers the entire state.<\/SPAN><\/P>

Miscellaneous Landslide Mapping is compiled landslide data from many sources focused on landslide mapping. Each project has its own protocol and methods, so it is up to the user to determine how best to interpret the landslide data. To avoid the risk of misinterpretation, invalid results, and erroneous conclusions, users should consider original map scale, collection methodology, original mapping purpose, currency of data, and any other conditions specific to every data element and each dataset as a whole.<\/SPAN><\/P>

Watershed Analysis Landslide Mapping polygons were created to support forest practices rules in identification of unstable slopes in various watersheds throughout the state. Rule-identified landform mapping was conducted using aerial photographs, maps (including geology, soil, and topographic), field observations, and limited lidar. Landforms were identified and mapped using a Watershed Analysis or the Landslide Hazard Zonation Protocol. All rule-identified landforms are not shown; only areas identified as landslides in the original watershed analyses are included in this data.<\/SPAN><\/P>

Reconnaissance-Scale Landslide Mapping is compiled landslides mapped from surveys immediately following widespread rain or rain-on-snow events in Washington. Mapping techniques for these large-scale surveys vary between aerial surveys from small aircraft, aerial photography, or lidar identification, with minimal field verification.<\/SPAN><\/P>

The Salish Sea Landforms identifies landforms along 2,200 miles of Salish Sea shoreline that have characteristics of deep-seated landslides, but lack the thorough investigation necessary to classify these landforms as landslides. All landforms in this layer were identified using historic aerial imagery and 3- to 6-foot LiDAR digital elevation models (DEM). Based on interpretation of LiDAR derivatives (such as hill shades, contour lines, and slope gradient) and aerial imagery, observations of geomorphic features representative of a deep-seated landslide were delineated in a GIS. Due to the method of data collection and the certainty of the data, this dataset should not be confused with a landslide inventory, which typically undergoes a thorough, historic aerial imagery analysis, field validation, and peer review. <\/SPAN><\/P>

Landslides from various projects may or may not have used lidar for landslide identification. Landslides in this compilation are mapped at various scales and with varied purpose. Many of these compilation layers are not statewide in extent \u2013 the absence of a mapped landslide in a particular location does not suggest that no landslide exists or that there is no landslide risk.<\/SPAN><\/P>

To avoid the risk of misinterpretation, invalid results, and erroneous conclusions, users must consider original map scale, collection methodology, currency of data, and any other conditions specific to every data element and each dataset as a whole. This dataset is not intended as a substitute for a detailed investigation of potential slope instability by a qualified practitioner. Site-specific analysis may give results that differ from those displayed on the map.<\/SPAN><\/P>

In areas where the Landslide Compilation is overlapped by the lidar-based Landslide Inventory, the overlapping zones have been attributed as \u2018superseded.\u2019 These layers are not displayed on the portal but are available in the GIS download of the Landslide Compilation.<\/SPAN><\/P>

<\/P><\/DIV><\/DIV><\/DIV>", "summary": "These data were produced to provide attribute and spatial information on landslides in Washington State. This data is non-regulatory and is intended for informational purposes. It may not be suitable for legal, engineering, forestry, or surveying purposes; but it is intended to assist planners, homeowners, regulators, and others by identifying areas to seek further geologic investigation in before developing, or areas to avoid. Users of this information should consider their intended application, and review or consult the accompanying documentation, to determine the usability of the data for themselves.", "title": "Landslide Compilation", "tags": [ "debris avalanche", "USA", "slumps", "mass wasting", "soil creep", "block slides", "geologic hazards", "shallow landslide", "rock falls", "lateral spreading", "slides", "deep seated landslide", "landslides", "Washington State" ], "type": "", "typeKeywords": [], "thumbnail": "", "url": "", "minScale": 150000000, "maxScale": 5000, "spatialReference": "", "accessInformation": "", "licenseInfo": "

The Washington Geological Survey (WGS) shall not be held liable for improper or incorrect use of the data described and/or contained herein. This product is provided 'as is' without warranty of any kind, either expressed or implied, including, but not limited to, the implied warranties of merchantability and fitness for a particular use. The Washington State Department of Natural Resources and the authors of this product will not be liable to the user of this product for any activity involving the product with respect to the following: (a) lost profits, lost savings, or any other consequential damages; (b) the fitness of the product for a particular purpose; or (c) use of the product or results obtained from use of the product. Although these data have been processed successfully on computers of WGS, no warranty, expressed or implied, is made by WGS regarding the use of these data on any other system, nor does the fact of distribution constitute or imply any such warranty.<\/SPAN><\/P><\/DIV><\/DIV><\/DIV>", "portalUrl": "" }