Identification_Information: Citation: Citation_Information: Originator: Brabb, E.E. Originator: Colgan, J.P. Originator: Best, T.C. Publication_Date: 1999 Title: Map showing inventory and regional susceptibility for Holocene debris flows and related fast moving landslides in the conterminous United States Geospatial_Data_Presentation_Form: map Series_Information: Series_Name: MF Issue_Identification: 2329 Publication_Information: Publication_Place: Menlo Park, CA Publisher: U.S. Geological Survey Description: Abstract: Debris flows, debris avalanches, mud flows and lahars are fast-moving landslides that occur in a wide variety of environments throughout the world. They are particularly dangerous to life and property because they move quickly, destroy objects in their paths, and can strike with little warning. The purpose of this map is to show where debris flows have occurred in the conterminous United States and where these slope movements might be expected in the future. Purpose: These data are intended for geographic display and analysis at the national level, and for large regional areas. It is not intended for hazard evaluation or other site-specific work, and should not be used for such. It can be used to determine where debris flow processes may be a problem and where additional information and investigation are warranted. Although the digital form of the data removes the constraint imposed by the scale of a paper map, the detail and accuracy inherent in map scale are also present in the digital data. The fact that this database was edited at a scale of 1:2,500,000 means that higher resolution information is not present in the data. Plotting at scales larger than 1:2,500,000 will not yield greater real detail, and it may reveal fine-scale irregularities below the intended resolution of the database. Similarly, where this database is used in combination with other data of higher resolution, the resolution of the combined output will be limited by the lower resolution of these data. No responsibility is assumed by the U.S. Geological Survey in the use of these data. Supplemental_Information: (This should ONLY contain information that does not fit in any other section.) Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 1928 Ending_Date: 1999 Currentness_Reference: All of the data on this map were compiled from reports published or field work conducted after the year 1928. No distinction was made between debris flow scars, made shortly after the events and debris flow deposits, which may be thousands of years old. We believe that all of the debris flows described in this report formed during the past 10,000 years (Holocene), but some of them could be older. Status: Progress: Complete Maintenance_and_Update_Frequency: Irregular Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: 172 East_Bounding_Coordinate: -66 North_Bounding_Coordinate: 72 South_Bounding_Coordinate: 18 Keywords: Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: debris flow Theme_Keyword: mud flow Theme_Keyword: lahar Theme_Keyword: debris avalanche Theme_Keyword: landslide Place: Place_Keyword_Thesaurus: U.S. Department of Commerce, 1995, Countries, Dependencies, Areas of Special Sovereignty, and Their Principal Administrative Divisions (Federal Information Processing Standard 10-4): Washington, D.C., National Institute of Standards and Technology. Place_Keyword: United States Place: Place_Keyword_Thesaurus: U.S. Department of Commerce, 1987, Codes for the Identification of the States, the District of Columbia and the Outlying Areas of The United States, and Associated Areas (Federal Processing Standard 5-2): Washington ,D.C., National Institute of Standards and Technology. Place_Keyword: USA Place_Keyword: Alabama Place_Keyword: Arizona Place_Keyword: Arkansas Place_Keyword: California Place_Keyword: Colorado Place_Keyword: Connecticut Place_Keyword: Delaware Place_Keyword: District of Columbia Place_Keyword: Florida Place_Keyword: Georgia Place_Keyword: Idaho Place_Keyword: Illinois Place_Keyword: Indiana Place_Keyword: Iowa Place_Keyword: Kansas Place_Keyword: Kentucky Place_Keyword: Louisiana Place_Keyword: Maine Place_Keyword: Maryland Place_Keyword: Massachusetts Place_Keyword: Michigan Place_Keyword: Minnesota Place_Keyword: Mississippi Place_Keyword: Missouri Place_Keyword: Montana Place_Keyword: Nebraska Place_Keyword: Nevada Place_Keyword: New Hampshire Place_Keyword: New Jersey Place_Keyword: New Mexico Place_Keyword: New York Place_Keyword: North Carolina Place_Keyword: North Dakota Place_Keyword: Ohio Place_Keyword: Oklahoma Place_Keyword: Oregon Place_Keyword: Pennsylvania Place_Keyword: Rhode Island Place_Keyword: South Carolina Place_Keyword: South Dakota Place_Keyword: Tennessee Place_Keyword: Texas Place_Keyword: Utah Place_Keyword: Vermont Place_Keyword: Virginia Place_Keyword: Washington Place_Keyword: West Virginia Place_Keyword: Wisconsin Place_Keyword: Wyoming Access_Constraints: None Use_Constraints: None. Acknowledgment of the National Atlas of the United States of America and (or) the U.S. Geological Survey would be appreciated in products derived from these data. Point_of_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Steve Kambly Contact_Organization: U.S. Geological Survey Contact_Address: Address_Type: mailing address Address: 561 National Center City: Reston State_or_Province: VA Postal_Code: 20192 Contact_Voice_Telephone: 703-648-5094 Contact_Electronic_Mail_Address: skambly@usgs.gov Data_Set_Credit: We are grateful to several state geologists and members of their staff who kindly reviewed a preliminary copy of the map and the bibliography and provided new information. We are particularly grateful to M. Lee Allison, State Geologist for Utah, and members of his staff who contributed a digital database of debris flow locations for Utah. We also wish to thank Stephen Ellen, Russell Campbell, Gerald Wieczorek, and David Howell for their reviews and help during various phases of the work. Native_Data_Set_Environment: The databases in this repot were compiled in ARC/INFO, a commercial Geographic Information System (Environmental Systems Research Institute, Redlands, California), with version 3.0 of the menu interface ALACARTE (Fitzgibbon and Wentworth, 1991, Fitzgibbon, 1991, Wentworth and Fitzgibbon, 1991). The files are in either GRID (ARC/INFO raster data) format or COVERAGE (ARC/INFO vector data) format. Coverages are stored in uncompressed ARC export format (ARC/INFO version 7.x). ARC/INFO export files (files with the .e00 extension) can be converted into ARC/INFO coverages in ARC/INFO (see below) and can be read by some other Geographic Information Systems, such as MapInfo via ArcLink and ESRI's ArcView (version 1.0 for Windows 3.1 to 3.11 is available for free from ESRI's web site: http://www.esri.com). The digital compilation was done in version 7.0.4 of ARC/INFO with version 3.0 of the menu interface ALACARTE (Fitzgibbon and Wentworth, 1991, Fitzgibbon, 1991, Wentworth and Fitzgibbon, 1991). Data_Quality_Information: Logical_Consistency_Report: No additional checks for topological consistency were performed on this data set. Completeness_Report: This data set includes an inventory of debris flows and related fast-moving landslides for the conterminous United States, and a susceptibility map covering the same area. This inventory is up-to-date as of August 1999, but there undoubtedly exists a significant amount of information that is not included in this report. Lineage: Source_Information: Source_Citation: Citation_Information: Originator: National Oceanic and Atmospheric Administration Publication_Date: 1991 Title: United States 30-second DTM Publication_Information: Publication_Place: Washington, DC Publisher: National Oceanic and Atmospheric Administration Type_of_Source_Media: Online Source_Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: Ending_Date: 1991 Source_Currentness_Reference: 1991 Source_Citation_Abbreviation: DEM Source_Contribution: Digital elevation values Process_Step: Process_Description: A Digital Elevation Model (DEM) released by the National Oceanic and Atmospheric Administration (NOAA) provides convenient nationwide data for the preparation of a slope map. The database consists of ground-surface elevations at 30 arc-second (approximately 1 km by 1 km) grid cells. Apparently these data were derived from the Army Map Service 1:250,000 topographic maps. However, several slope maps were prepared from this database using ARC/INFO, a commercial GIS software program. To calculate the slope at each one-kilometer grid cell, the process fits a quadratic surface to the elevation values of a 3 cell by 3 cell box surrounding the grid cell for which the slope is to be calculated. The slope assigned to the middle cell is the maximum slope of the quadratic surface at that point. Source_Used_Citation_Abbreviation: DEM Process_Date: 1999 Source_Produced_Citation_Abbreviation: Slope map Process_Step: Process_Description: Brabb and others (1989) have discussed several problems with the database. One of these concerns the average value for the slope over a 9km square area. This figure is generally much flatter than the actual value for slopes within the selected area. Map values of one or two degrees may correspond to slopes steeper than the 25- degree value targeted for the susceptibility map. Because of this discrepancy, the map is referred to as a slope index map, giving relative slope rather than actual slope at any specific area. Several slope index maps were prepared to try to find slopes steeper than 25 degrees where debris flows might be expected in the future. The maps were adjusted by trial and error to incorporate the largest number of debris-flow points without including large, gently sloping areas where no debris flows are expected. We eventually adopted a map with a slope index steeper than 3 percent, which includes about 75 percent of the debris flows mapped. Only individual debris-flow locations were used to compute the percentage of debris flows in each slope category, because the locations of debris flows within the polygon areas are too uncertain for this purpose. The other debris flows may occur in areas where more gentle average slopes contain steep slopes of limited extent, such as cliffs along rivers and lakes that are too small to be detected in the one-kilometer grid cell. Alternatively, some features mapped as debris flows may not be debris flows. Source_Used_Citation_Abbreviation: Slope map Process_Date: 1999 Source_Produced_Citation_Abbreviation: Susceptibility map Process_Step: Process_Description: The susceptibility map was combined with a digital shaded-relief map to make the tiff image file for map display. This was done using the grid commands Source_Used_Citation_Abbreviation: Susceptibility map Source_Used_Citation_Abbreviation: DEM Process_Date: 1999 Source_Produced_Citation_Abbreviation: Shaded-relief susceptibility Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Raster Raster_Object_Information: Raster_Object_Type: Grid Cell Row_Count: 4152 Column_Count: 7230 Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Planar: Map_Projection: Map_Projection_Name: Lambert Azimuthal Equal Area Lambert_Azimuthal_Equal_Area: Longitude_of_Projection_Center: -100.00 Latitude_of_Projection_Center: 45.00 False_Easting: 0.0 False_Northing: 0.0 Planar_Coordinate_Information: Planar_Coordinate_Encoding_Method: coordinate pair Coordinate_Representation: Abscissa_Resolution: 1.0 Ordinate_Resolution: 1.0 Planar_Distance_Units: METERS Geodetic_Model: Horizontal_Datum_Name: North American Datum of 1983 Ellipsoid_Name: GRS1980 Semi-major_Axis: 6378206.4 Denominator_of_Flattening_Ratio: 294.98 Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Label: Debris-flow susceptibility grid cell Entity_Type_Definition: Any of the data elements in the debris-flow susceptibility file Entity_Type_Definition_Source: author Attribute: Attribute_Label: Debris-flow susceptibility grid cell value Attribute_Definition: The value refers to color of the raster cell in the tiff file. The various shades of pink represent areas that are susceptible to debris flows, and the shades of gray represent areas that are likely not at high risk for debris Attribute_Definition_Source: author Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 1 Range_Domain_Maximum: 15 Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: Earth Science Information Center, U.S. Geological Survey Contact_Address: Address_Type: mailing address Address: 507 National Center City: Reston State_or_Province: VA Postal_Code: 20192 Contact_Voice_Telephone: 1-888-ASK-USGS (1-888-275-8747) Hours_of_Service: 0800-1600 Contact_Instructions: In addition to the address above there are other ESIC offices throughout the country. A full list of these offices is at http://mapping.usgs.gov/esic/esic_index.html Distribution_Liability: Although these data have been processed successfully on a computer system at the U.S. Geological Survey, no warranty expressed or implied is made by the U.S. Geological Survey regarding the utility of the data on any other system, nor shall the act of distribution constitute any such warranty. No responsibility is assumed by the U.S. Geological Survey in the use of these data. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Metadata_Reference_Information: Metadata_Date: 19990122 Metadata_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Peg Rawson Contact_Organization: U.S. Geological Survey Contact_Address: Address_Type: mailing address Address: 521 National Center City: Reston State_or_Province: VA Postal_Code: 20192 Contact_Voice_Telephone: 703-648-4183 Contact_Electronic_Mail_Address: mrawson@usgs.gov Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998 Metadata_Security_Information: Metadata_Security_Classification_System: None Metadata_Security_Classification: Unclassified Metadata_Security_Handling_Description: None