Landslide initiation locations in Nicaragua

Frequently anticipated questions:

• What does this data set describe?
  1. How might 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 might this data set be cited?
   Cannon, Susan H., Haller, Kathleen M., Ekstrom, Ingrid, Schweig, Eugene S. III, Devoli, Graziella, Moore, David W., Rafferty, Sharon A., and Tarr, Arthur C., 2001, Landslide initiation locations in Nicaragua: U.S. Geological Survey Open-File Report 01-412-A, U.S. Geological Survey, Denver, Colorado.

   Online Links:

   • http://pubs.usgs.gov/of/2001/ofr-01-0412-a/

   This is part of the following larger work.
   Cannon, Susan H., Haller, Kathleen M., Ekstrom, Ingrid, Schweig, Eugene S. III, Devoli, Graziella, Moore, David W., Rafferty, Sharon A., and Tarr, Arthur C., 2001, Landslide response to Hurricane Mitch rainfall in seven study areas in Nicaragua: U.S. Geological Survey Open-File Report 01-412-A, U.S. Geological Survey, Denver, Colorado.

   Online Links:

   • http://pubs.usgs.gov/of/2001/ofr-01-0412-a/

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -86.891144
   East_Bounding_Coordinate: -85.780037
   North_Bounding_Coordinate: 13.781081
   South_Bounding_Coordinate: 12.832439
   

3. What does it look like?

   http://geo-nsdi.er.usgs.gov/metadata/open-file/01-412/01-412.png (PNG)

   Map showing locations of study area in Nicaragua, 717x652 pixels, 14.5k bytes.

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

   Calendar_Date: Oct-1998

   Currentness_Reference:

   ground condition

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):
      • Entity point (8645)
      • Point (4)
      • GT-polygon composed of chains (4100)
      • Point (16)
   2. What coordinate system is used to represent geographic features?
      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitude and longitude values are specified in Decimal degrees. The horizontal datum used is D_WGS_1984.
      The ellipsoid used is WGS_1984.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257224.
      
7. How does the data set describe geographic features?

Who produced the data set?

1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
   • Susan H. Cannon
   • Kathleen M. Haller
   • Ingrid Ekstrom
   • Eugene S. Schweig III
   • Graziella Devoli
   • David W. Moore
   • Sharon A. Rafferty
   • Arthur C. Tarr
2. Who also contributed to the data set?
3. To whom should users address questions about the data?
   Susan H Cannon

   U.S. Geological Survey, CR

   Mail Stop 966

   P.O. Box 25046

   Lakewood, CO
   

   USA

   303-273-8604 (voice)

   303-273-8600 (FAX)

   cannon@usgs.gov

Why was the data set created?

The passage of Hurricane Mitch through Central America in October and November 1998 caused widespread and devastating flooding and landsliding. In this data set we document the locations where landslides initiated in response to the rainfall that accompanied Hurricane Mitch in seven study areas in Nicaragua.

How was the data set created?

1. From what previous works were the data drawn?

   1:60,000 aerial photos (source 1 of 2)

   Defense Threat Reduction Agency.

   Type_of_Source_Media: aerial photographs
   Source_Scale_Denominator: 60000
   

   1:30,000 aerial photos (source 2 of 2)

   Type_of_Source_Media: aerial photographs
   Source_Scale_Denominator: 30000
   

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

   (process 1 of 4)

   Aerial photographs taken between December 4 and December 19, 1998 under the Open Skies program of the Defense Threat Reduction Agency were used to map the intiation locations of the landslides shown on the maps. The aerial photographs are at 1:60,000-scale, and 1:30,000-scale for portions of the Matagalpa and Jinotega/San Rafael del Norte study areas. Digital Raster Graphic (DRG) scanned images of 1:50,000-scale quadrangles projected to Transverse Mercator were used as base maps for the mapping. We mapped landslides by first identifying them on the aerial photographs using a mirror stereoscope and then manually plotting each landslide and its affected area by inspection onto the base maps. In some cases, the base maps were enlarged to 1:25,000-scale to facilitate mapping.

   (process 2 of 4)

   Field reconnaissance from April 25 through May 6, 2000 resulted in limited verification of the landslide and related effects mapping. Because of the large areal extent of the study areas and difficulties of access, we visited only a few, small areas. We observed as few as 5% of the landslides in some study areas and as many as 40% of the landslides in others. During this reconnaissance, we mapped the locations and extents of some landslides outside the coverage of the aerial photography. This mapping represents only features that we observed, and is not representative of all the landslide activity in the area.

   (process 3 of 4)

   Following field verification, a point representing the initiation location of each landslide was digitized. This point was located as the highest elevation point within the landslide polygon.

   Date: 05-Dec-2001 (process 4 of 4)

   Creation of original metadata record Person who carried out this activity:
   

   Richard L Dart

   U.S. Geological Survey, CR

   Mail Stop 966

   P.O. Box 25046

   Lakewood, CO
   

   USA

   303-273-8637 (voice)

   303-273-8600 (FAX)

   dart@usgs.gov

3. What similar or related data should the user be aware of?
   Cannon, Susan H., Haller, Kathleen M., Ekstrom, Ingrid, Schweig, Eugene S. III, Devoli, Graziella, Moore, David W., Rafferty, Sharon A., and Tarr, Arthur C., 2001, Respuesta a los Desprendimientos de Tierra Ocasionados por las Lluvias Torrenciales del Huracán Mitch en Siete Áreas de Estudio de Nicaragua: U.S. Geological Survey Open-File Report 01-412-B, U.S. Geological Survey, Denver, Colorado.

   Online Links:

   • http://pubs.usgs.gov/of/2001/ofr-01-0412-b/

   Other_Citation_Details: Spanish version of 01-412-A
   

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

1. How well have the observations been checked?
   Attribute accuracy was assured by visually comparing the compilation copy with the plotted map on which the landslide initiation locations were mapped.
2. How accurate are the geographic locations?
   The small scale of the aerial photographs, and the mapping method of manually transferring observed features to the base maps, dictates that the locations of the landslide initiation locations are accurate to within about 200m.
3. How accurate are the heights or depths?
   
4. Where are the gaps in the data? What is missing?
   Completeness was assured by visually inspecting the compilation map overlaid on the plotted map looking for missing initiation points.
5. How consistent are the relationships among the observations, including topology?
   Registration accuracy was checked by inspecting plots of the data and graticule overlaid on a Digital Raster Graphic (DRG) of the base map. This assured that the initiation points fell within the landslide polygons.

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:

Should only be used in maps whose scale is smaller than 1:50,000.

1. Who distributes the data set? (Distributor 1 of 1)
   
   USGS Information Services

   Box 25286 Denver Federal Center

   Denver, CO
   

   USA

   1-888-ASK-USGS (voice)

   303-202-4693 (FAX)

   ask@usgs.gov
2. What's the catalog number I need to order this data set? USGS Open-File Report 01-412
3. What legal disclaimers am I supposed to read?

   This report is preliminary and has not been reviewed for conformity with U.S.Geological Survey editorial standards nor with the North American Stratigraphic Code.Any use of trade names in this publication is for descriptive purposes only and does not imply endorsement by the U.S.Government.

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

     Data format:	Landslide areas or initiation locations in format ARCE (version 8.1) Size: 1.2
     Network links:	http://pubs.usgs.gov/of/2001/ofr-01-0412-a/digital_files/IPOINT_DD.E00

     Data format:	Landslides in format Shapefile (version 1.0) Size: 0.5
     Network links:	http://pubs.usgs.gov/of/2001/ofr-01-0412-a/digital_files/IPOINT_DD.SHP http://pubs.usgs.gov/of/2001/ofr-01-0412-a/digital_files/IPOINT_DD.SHX http://pubs.usgs.gov/of/2001/ofr-01-0412-a/digital_files/IPOINT_DD.DBF

   • Cost to order the data: none

Who wrote the metadata?

Dates:

Last modified: 13-Jun-2016

Metadata author:

Peter N Schweitzer

USGS Midwest Area

Collection manager, USGS Geoscience Data Clearinghouse, http://geo-nsdi.er.usgs.gov/

Mail Stop 954

12201 Sunrise Valley Dr

Reston, VA

USA

703-648-6533 (voice)

703-648-6252 (FAX)

pschweitzer@usgs.gov

Metadata standard:

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