Identification_Information: Citation: Citation_Information: Originator: Douglas M. Morton Originator: Rachel M.H. Alvarez Originator: Russell H. Campbell Publication_Date: 200301 Title: Preliminary Soil-Slip Susceptibility Maps, Southwestern California Edition: Version 1.0 Geospatial_Data_Presentation_Form: raster digital data Series_Information: Series_Name: U.S. Geological Survey Open-File Report Issue_Identification: USGS OF 03-17 Publication_Information: Publication_Place: Menlo Park, California Publisher: U.S. Geological Survey Online_Linkage: http://geopubs.wr.usgs.gov/open-file/of03-17 Description: Abstract: This data set maps the soil-slip susceptibility for several areas in southwestern California. Created using Environmental Systems Research Institute's ARC/INFO software, the data base consists of raster maps containing grid cells coded with soil-slip susceptibility values. In addition, the data set includes the following graphic and text products: (1) postscript graphic plot files containing the soil-slip susceptibility map, topography, cultural data, and a key of the colored map units, and (2) PDF and text files of the Readme (including the metadata file as an appendix) and accompanying text, and a PDF file of the plot files. Intense winter rains commonly generated debris flows in upland areas of southwestern California. These debris flows initiate as small landslides referred to as soil slips. Most of the soil slips mobilize into debris flows that travel down slope at varying speeds and distances. The debris flows can be a serious hazard to people and structures in their paths. The soil-slip susceptibility maps identify those natural slopes most likely to be the sites of soil slips during periods of intense winter rainfall. The maps were largely derived by extrapolation of debris-flow inventory data collected from selected areas of southwestern California. Based on spatial analyses of soil slips, three factors in addition to rainfall, were found to be most important in the origin of soil slips. These factors are geology, slope, and aspect. Geology, by far the most important factor, was derived from existing geologic maps. Slope and aspect data were obtained from 10-meter digital elevation models (DEM). Soil-slip susceptibility maps at a scale of 1:24,000 were derived from combining numerical values for geology, slope, and aspect on a 10-meter cell size for 128 7.5’ quadrangles and assembled on 1:100,000-scale topographic maps. The resultant maps of relative soil-slip susceptibility represent the best estimate generated from available debris-flow inventory maps and DEM data. Purpose: These data sets were derived to describe the relative soil-slip susceptibility for upland areas of southwestern California. Although released on a 1:100,000-scale topographic base, the data were derived at a scale of 1:24,000 and as such can be transferred from 1:100,000-scale to 1:24,000-scale without any loss of accuracy. The maps are not intended to be used at any scale larger than 1:24,000. Supplemental_Information: none Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 2003/01 Currentness_Reference: Not for use after June, 2003 Status: Progress: Complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -120.00446939 East_Bounding_Coordinate: -116.8742505 North_Bounding_Coordinate: 34.52044023 South_Bounding_Coordinate: 32.49939779 Keywords: Theme: Theme_Keyword_Thesaurus: none Theme_Keyword: Soil slips Theme_Keyword: Debris flows Place: Place_Keyword_Thesaurus: none Place_Keyword: California Place_Keyword: Southwestern California Place_Keyword: Los Angeles County Place_Keyword: Orange County Place_Keyword: Riverside County Place_Keyword: San Bernardino County Place_Keyword: San Diego County Place_Keyword: Santa Barbara County Place_Keyword: Ventura County Access_Constraints: none Use_Constraints: This data base is not to be used at a scale larger than 1:24,000. Point_of_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Douglas M. Morton Contact_Organization: U.S. Geological Survey, Western Region, Earth Surface Processes Team Contact_Position: Project geologist Contact_Address: Address_Type: mailing address Address: U.S. Geological Survey Address: Department of Earth Sciences Address: University of California, Riverside City: Riverside State_or_Province: California Postal_Code: 92521 Country: United States of America Contact_Voice_Telephone: (909) 276-6397 Contact_Facsimile_Telephone: (909) 276-6295 Contact_Electronic_Mail_Address: scamp@usgs.gov Data_Set_Credit: Geologic mapping and digital preparation of this report were sponsored jointly by (1) the National Cooperative Geologic Mapping Program of the U.S. Geological Survey, (2) the California Geological Survey, and (3) the Southern California Areal Mapping Project (SCAMP). The California Geological Survey graciously provided geologic map data and critical input. Native_Data_Set_Environment: Windows_NT, 5.0, Intel ARC/INFO version 8.1 Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: The map meets national geologic map standards. The digital elevation data meet U.S. Geological National Digital Elevation Model standards. Logical_Consistency_Report: Not applicable for raster data. Completeness_Report: The map reflects the most accurate geologic map data and DEM data currently available to the U.S. Geological Survey. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: For accuracy information for DEM data refer to the U.S. Geological Survey Digital Elevation Models, Data User's Guide 5. Complete reference is in the explanatory text document. Lineage: Process_Step: Process_Description: Process included mapping debris flows from several generations of aerial photographs in selected areas of southwestern California. Debris flows were transferred by inspection to 7.5’ topographic quadrangle maps to produce debris flow inventory maps. Debris flow inventory maps were digitized in a GIS system (Arc/Info). Geologic data were obtained from digital geologic data bases from various sources. Digital elevation data were obtained from U.S. Geological Survey digital elevation models (DEM). Susceptibility values were the product of numerical values assigned to geologic map units, slope, and aspect. Process_Date: 200209-200301 Process_Step: Process_Description: First draft of metadata created by Rachel Alvarez using FGDCMETA.AML ver. 1.2 05/14/98 on ARC/INFO data set Process_Date: 20030108 Process_Step: Process_Description: Digital database review by Scott Graham. Process_Date: 20030113 Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Raster Raster_Object_Information: Raster_Object_Type: Grid Cell Row_Count: 22569 Column_Count: 29031 Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Planar: Grid_Coordinate_System: Grid_Coordinate_System_Name: Universal Transverse Mercator Universal_Transverse_Mercator: UTM_Zone_Number: 11 Transverse_Mercator: Scale_Factor_at_Central_Meridian: 1 Longitude_of_Central_Meridian: -118 26 15 Latitude_of_Projection_Origin: 32 30 False_Easting: 0 False_Northing: 0 Planar_Coordinate_Information: Planar_Coordinate_Encoding_Method: coordinate pair Coordinate_Representation: Abscissa_Resolution: 10.0 Ordinate_Resolution: 10.0 Planar_Distance_Units: Meters Geodetic_Model: Horizontal_Datum_Name: North American Datum of 1927 Ellipsoid_Name: Clarke 1866 Semi-major_Axis: 6378206.4 Denominator_of_Flattening_Ratio: 294.98 Entity_and_Attribute_Information: Overview_Description: Entity_and_Attribute_Overview: Version 1.0 of the Preliminary Soil-Slip Susceptibility Maps, Southwestern California comprises seven ARC/INFO grids, la_sus, lb_sus, ocs_sus, sbern_sus, sd_sus, sa_sus, sbarb_sus, which contain soil-slip susceptibility values. The item names and definitions are the same for each raster data set and are as follows: > > >*_sus.vat >COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC ALTERNATE NAME > 1 VALUE 4 10 B - > 5 COUNT 4 10 B - > 9 SUSCODE 8 8 N 3 > > >*_sus.sta >COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC ALTERNATE NAME > 1 MIN 8 15 F 3 > 9 MAX 8 15 F 3 > 17 MEAN 8 15 F 3 > 25 STDV 8 15 F 3 > > The item suscode contains the susceptibility values. Entity_and_Attribute_Detail_Citation: none Detailed_Description: Entity_Type: Entity_Type_Label: *.vat Entity_Type_Definition: Susceptibility values identified in each of the seven mapped areas (the Santa Barbara 100K sheet, the Los Angeles 100K sheet, the south half of the San Bernardino 100K sheet, the Long Beach 100K sheet, the Santa Ana 100K sheet, the Oceanside 100K sheet, and the San Diego and western El Cajon 100K sheets) Attribute: Attribute_Label: suscode Attribute_Definition: number corresponding to a susceptibility value = not included in low, moderate or high Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: 0 Enumerated_Domain_Value_Definition: A value of 0 indicates the cell does not meet the criteria needed to fall into the low, moderate or high susceptibility categories. Susceptibility values identified in each of the seven mapped areas (the Santa Barbara 100K sheet, the Los Angeles 100K sheet, the south half of the San Bernardino 100K sheet, the Long Beach 100K sheet, the Santa Ana 100K sheet, the Oceanside 100K sheet, and the San Diego and western El Cajon 100K sheets). Attribute: Attribute_Label: suscode Attribute_Definition: number corresponding to a susceptibility value = low Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 6 Range_Domain_Maximum: 999 Attribute: Attribute_Label: suscode Attribute_Definition: number corresponding to a susceptibility value = moderate Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 1000 Range_Domain_Maximum: 3250 Attribute: Attribute_Label: suscode Attribute_Definition: number corresponding to a susceptibility value = high Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 3251 Range_Domain_Maximum: 5000 Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Information Services Contact_Address: Address_Type: mailing address Address: Box 25286 Denver Federal Center City: Denver State_or_Province: Colorado Postal_Code: 80225 Country: USA Contact_Voice_Telephone: (303) 202-4700 Contact_Facsimile_Telephone: (303) 202-4693 Distribution_Liability: The U.S. Geological Survey (USGS) provides these geographic data "as is". The USGS makes no guarantee or warranty concerning the accuracy of information contained in the geographic data. The USGS further makes no warranties, either expressed or implied as to any other matter whatsoever, including, without limitation, the condition of the product, or its fitness for use lies entirely with the user. Although these data have been processed successfully on computers at the USGS, no warranty, expressed or implied, is made by the USGS regarding the use of these data on any other system, nor does the fact of distribution constitute or imply any such warranty. In no event shall the USGS have any liability whatsoever for payment of any consequential, incidental, indirect, special, or tort damages of any kind, including, but not limited to, any loss of profits arising out of use of or reliance on the geographic data or arising out of the delivery, installation, operation, or support by USGS. These digital map databases, 1:100,000 scale, and any derivative maps thereof, is not meant to be used or displayed at any scale larger than 1:24,000 (e.g., 1:12,000). Metadata_Reference_Information: Metadata_Date: 20030108 Metadata_Review_Date: 20030113 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: Rachel M.H. Alvarez Contact_Position: Geologist Contact_Address: Address_Type: mailing address Address: U.S. Geological Survey Address: Department of Earth Sciences Address: University of California, Riverside City: Riverside State_or_Province: California Postal_Code: 92521 Country: USA Contact_Voice_Telephone: (909) 276-6397 Contact_Facsimile_Telephone: (909) 276-6295 Contact_Electronic_Mail_Address: rhauser@usgs.gov Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998 Metadata_Access_Constraints: none Metadata_Use_Constraints: none