Landslide Incidence and Susceptibility in the Conterminous United States

Frequently-anticipated questions:

• What does this data set describe?
  1. How should this data set be cited?
  2. What geographic area does the data set cover?
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
  5. What is the general form of this data set?
  6. How does the data set represent geographic features?
  7. How does the data set describe geographic features?
• Who produced the data set?
  1. Who are the originators of the data set?
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
• Why was the data set created?
• How was the data set created?
  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
  3. What similar or related data should the user be aware of?
• How reliable are the data; what problems remain in the data set?
  1. How well have the observations been checked?
  2. How accurate are the geographic locations?
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
  5. How consistent are the relationships among the data, including topology?
• How can someone get a copy of the data set?
  1. Are there legal restrictions on access or use of the data?
  2. Who distributes the data?
  3. What's the catalog number I need to order this data set?
  4. What legal disclaimers am I supposed to read?
  5. How can I download or order the data?
• Who wrote the metadata?

What does this data set describe?

1. How should this data set be cited?

   Godt, Jonathan W. , 200102, Landslide Incidence and Susceptibility in the Conterminous United States: U.S. Geological Survey Open-File Report 97-289, U.S. Geological Survey, Reston, VA.

   Online Links:

   • <http://nationalatlas.gov/atlasftp.html?openChapters=chpgeol#chpgeol>

   Other_Citation_Details:

   These data were originally published as: Godt, J.W., 1997, Digital Representation of Landslide Overview Map of the Conterminous United States: U.S. Geological Survey Open-File Report 97-289, scale 1:4,000,000. Available online at <http://landslides.usgs.gov/learningeducation/nationalmap/index.php>.

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -125

   East_Bounding_Coordinate: -66

   North_Bounding_Coordinate: 50

   South_Bounding_Coordinate: 24

3. What does it look like?

4. Does the data set describe conditions during a particular time period?

   Calendar_Date: 2001

   Currentness_Reference: Publication date

5. What is the general form of this data set?

   Geospatial_Data_Presentation_Form: Vector digital data

6. How does the data set represent geographic features?
   1. How are geographic features stored in the data set?

      This is a Vector data set. It contains the following vector data types (SDTS terminology):

      • GT-polygon composed of chains (2813)

   2. What coordinate system is used to represent geographic features?

      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.000278. Longitudes are given to the nearest 0.000278. Latitude and longitude values are specified in Decimal degrees.

      The horizontal datum used is North American Datum of 1983.
      The ellipsoid used is GRS1980.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257222.
      

7. How does the data set describe geographic features?

   Landslide susceptibility and incidence polygons (described by lsoverp020.dbf)

   Landslide incidence and susceptibility (Source: U.S. Geological Survey Professional Paper 1183)

   Shape

   The representation of the entity in the data. (Source: U.S. Geological Survey)

   Value	Definition
   polygon	2-dimensional element

   Area

   The size of the shape in coverage units. In the distributed file, coverage units represent square decimal degrees. (Source: National Atlas of the United States)

   Range of values
   Minimum:	0.000
   Maximum:	618.453

   Perimeter

   The perimeter of the shape in coverage units. In the distributed file, coverage units represent decimal degrees. (Source: National Atlas of the United States)

   Range of values
   Minimum:	0.008
   Maximum:	1515.642

   Lsoverp020

   Internal feature number. (Source: National Atlas of the United States)

   Range of values
   Minimum:	2
   Maximum:	2814

   Inc_sus

   A descriptor of landslide incidence and susceptibility. (Source: U.S. Geological Survey)

   Value	Definition
   combo-hi	High susceptibility to landsliding and moderate incidence.
   high	High landslide incidence (more than 15% of the area is involved in landsliding).
   low	Low landslide incidence (less than 1.5 % of the area is involved in landsliding).
   mod	Moderate landslide incidence (1.5 - 15% of the area is involved in landsliding).
   no-data	No data exist for these areas.
   sus-high	High susceptibility to landsliding and low incidence.
   sus-mod	Moderate susceptibility to landsliding and low incidence.

Who produced the data set?

1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
   • Jonathan W. Godt

2. Who also contributed to the data set?

   Damon Sather and Jonathan Godt performed the laborious task of integrating the thematic data with the National Atlas coastline data.

3. To whom should users address questions about the data?
   Lynn Highland
   U.S. Geological Survey, National Landslide Information Center
   Director
   MS 966 Denver Federal Center Box 25046
   Denver, CO 80225
   USA
   

   800-654-4966 (voice)
   303-273-8600 (FAX)
   [email protected]
   

   Contact_Instructions: e-mail is the preferred method of contact

Why was the data set created?

These data are intended for geographic display and analysis at the national level, and for large regional areas. The data should be displayed and analyzed at scales appropriate for 1:4,000,000-scale data. No responsibility is assumed by the U.S. Geological Survey in the use of these data.

How was the data set created?

1. From what previous works were the data drawn?

   LSOVER (source 1 of 2)

   Radbruch-Hall, D.H., Colton, R.B., Davies, W.E., Lucchitta, Ivo, Skipp, B.A., and Varnes, D.J., 1982, Landslide Overview Map of the Conterminous United States: U.S. Geological Survey Professional Paper 1183, U.S. Geological Survey, Washington, DC.

   Type_of_Source_Media: Stable-base material

   Source_Scale_Denominator: 3,750,000

   Source_Contribution: Spatial and attribute information

   Coastlines (source 2 of 2)

   U.S. Geological Survey, 1999, State Boundaries of the United States: U.S. Geological Survey, Reston, VA.

   Type_of_Source_Media: Online

   Source_Scale_Denominator: 2,000,000

   Source_Contribution: Spatial and attribute information

2. How were the data generated, processed, and modified?

   Date: 1997 (process 1 of 4)

   Landslide incidence and susceptibility polygons were digitized from the original stable-base manuscripts at 1:3,750,000 from U.S. Geological Survey Professional Paper 1183.

   Person who carried out this activity:
   

   Jonathan W. Godt
   U.S. Geological Survey
   MS 966 Denver Federal Center Box 25046
   Denver, CO 80225
   USA
   

   303-273-8626 (voice)
   303-273-8600 (FAX)
   [email protected]
   

   Contact_Instructions: e-mail is the preferred method of contact

   Data sources used in this process:

   • LSOVER

   Date: 2000 (process 2 of 4)

   Polygons were closed along the coastline using the National Atlas coastline file. Minor revisions were made to spatial and attribute information in consultation with one of the original authors (D.J. Varnes).

   Data sources used in this process:

   • Coastlines

   Date: 2000 (process 3 of 4)

   Sliver polygons along State lines were eliminated by merging the polygons with the appropriate larger polygon to which they belonged. Adjacent polygons with the same descriptor of landslide incidence and susceptibility (inc_sus) were merged. Interior State lines were deleted and the attribution was checked. A value of 'no-data' was applied to water areas such as Puget Sound and the Great Lakes.

   Date: 2001 (process 4 of 4)

   Alaska, Hawaii, Puerto Rico, and the U.S. Virgin Islands were removed from the file.

3. What similar or related data should the user be aware of?

How reliable are the data; what problems remain in the data set?

1. How well have the observations been checked?

   The data are accurate, within visible tolerances, to the original manuscripts.

2. How accurate are the geographic locations?

   No tests for horizontal accuracy have been performed on this map layer.

3. How accurate are the heights or depths?

4. Where are the gaps in the data? What is missing?

   This map layer is an overview of landsliding in the conterminous United States. The data are thematic and general in nature. There is no intention to fully describe the extent of landsliding in the conterminous United States.

5. How consistent are the relationships among the observations, including topology?

   Digital data were visually inspected and agree with the original manuscripts.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?

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.

1. Who distributes the data set? (Distributor 1 of 1)
   Earth Science Information Center, U.S. Geological Survey
   507 National Center
   Reston, VA 20192
   

   1-888-ASK-USGS (1-888-275-8747) (voice)
   

   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://ask.usgs.gov/esic_index.html>.

2. What's the catalog number I need to order this data set?

3. What legal disclaimers am I supposed to read?

   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.

4. How can I download or order the data?
   • Availability in digital form:

     Data format:	ESRI Shapefile
     Network links:	<http://nationalatlas.gov/atlasftp.html?openChapters=chpgeol#chpgeol>

     Data format:	SDTS
     Network links:	<http://nationalatlas.gov/atlasftp.html?openChapters=chpgeol#chpgeol>

   • Cost to order the data: There is no charge for the map layer.

Who wrote the metadata?

Dates:

Last modified: 21-Jun-2006

Metadata author:

Peg Rawson
National Atlas of the United States
12201 Sunrise Valley Dr
Reston, VA 20192

703-648-4183 (voice)
[email protected]

Metadata standard:

FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)