Elevation Contours, NE quadrant of Steep Gully quadrangle, Louisiana, UTM 15 NAD83, Louisiana Federal Emergency Management Agency (FEMA)Rapides Parish, Louisiana under the Watershed Concepts contract number EMT-2002-CO-0048, Task Order 013. [c_3009202ne]

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?

Title:

Elevation Contours, NE quadrant of Steep Gully quadrangle, Louisiana, UTM 15 NAD83, Louisiana Federal Emergency Management Agency (FEMA)Rapides Parish, Louisiana under the Watershed Concepts contract number EMT-2002-CO-0048, Task Order 013. [c_3009202ne]

Abstract:

This is a line dataset of elevation contours over the NE quadrant of the Steep Gully quadrangle, Louisiana. The data were derived from LIDAR measurements performed in 2002, and are presented at a contour interval of two feet. These data were produced for the Louisiana Federal Emergency Management Agency (FEMA) Rapides Parish, Louisiana under the Watershed Concepts contract number EMT-2002-CO-0048, Task Order 013.

Supplemental_Information:

The metadata for this image are encapsulated into several documents. The metadata are not complete if you did not recieve the following files along with the data set:

c_3009202ne.mtd - this metadata in mp (metadata parser) compatible ASCII text form
c_3009202ne.html - this metadata in HTML form
c_3009202ne_faq.html - this metadata presented as Questions and Answers
c_3009202ne.sgml - this metadata in SGML form
c_3009202ne.xml - this metadata in XML form

The information depicted on this map represents the results of the survey on the dates indicated and can only be considered as indicating the general conditions existing at the time.

1. How should this data set be cited?

   Concepts, Watershed, 2003, Elevation Contours, NE quadrant of Steep Gully quadrangle, Louisiana, UTM 15 NAD83, Louisiana Federal Emergency Management Agency (FEMA)Rapides Parish, Louisiana under the Watershed Concepts contract number EMT-2002-CO-0048, Task Order 013. [c_3009202ne].

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -90.5625

   East_Bounding_Coordinate: -90.5000

   North_Bounding_Coordinate: +30.9375

   South_Bounding_Coordinate: +30.8750

3. What does it look like?

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

   Calendar_Date: Feb-2002

   Currentness_Reference:

   Approximate date of LIDAR survey used to build the source data for this data set

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

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):

      • Network chain, planar graph

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

      Grid_Coordinate_System_Name: Universal Transverse Mercator

      Universal_Transverse_Mercator:

      UTM_Zone_Number: 15

      Transverse_Mercator:

      Scale_Factor_at_Central_Meridian: 0.9996

      Longitude_of_Central_Meridian: -93.000000

      Latitude_of_Projection_Origin: +00.000000

      False_Easting: 500000

      False_Northing: 0

      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 0.001
      Ordinates (y-coordinates) are specified to the nearest 0.001
      Planar coordinates are specified in Meters

      The horizontal datum used is North American Datum of 1983.
      The ellipsoid used is Geodetic Reference System 80.
      The semi-major axis of the ellipsoid used is 6378137.
      The flattening of the ellipsoid used is 1/298.257.
      

      Vertical_Coordinate_System_Definition:

      Altitude_System_Definition:

      Altitude_Datum_Name: North American Vertical Datum of 1988

      Altitude_Resolution: 2

      Altitude_Distance_Units: Survey Feet

      Altitude_Encoding_Method: Attribute values

7. How does the data set describe geographic features?

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

2. Who also contributed to the data set?

3. To whom should users address questions about the data?

   Watershed Concepts
   c/o David Key, P.E.
   3333 Regency Parkway, Suite 120
   Cary, North Carolina 27511
   

   (919)868-5155 (voice)
   

Elevation contour data are a fundamental base map layer for large scale mapping and GIS analysis. The user should be aware that elevation contour models produced by computer are highly sensitive to the algorithm employed and the parameters of the algorithm. As a result, it is easily possible to get to differing results from the same source data. The algorithm and parameters employed to produce this contour model were deemed acceptable for reasons of appearance and processing time. These data will also be acceptable for most 12000 scale maps.

1. From what previous works were the data drawn?

   LAT_3009202ne (source 1 of 2)

   Concepts, Watershed, 2003, Digital Elevation Model (ArcInfo lattice), NE quadrant of Steep Gully quadrangle, Louisiana, UTM 15 NAD83, Louisiana Federal Emergency Management Agency (FEMA) Project - Phase 2 of Louisiana LIDAR Data Development: Rapides Parish, Louisiana under the Watershed Concepts contract number EMT-2002-CO-0048, Task Order 013. [lat_3009202ne].

   Type_of_Source_Media: computer file

   Source_Contribution:

   Digital Elevation Model (ArcInfo lattice), Rapides Parish, Louisiana under the Watershed Concepts contract number EMT-2002-CO-0048, Task Order 013. [lat_3009202ne]

   BHY_3009202ne (source 2 of 2)

   Concepts, Watershed, 2003, Hydrography Breakline Data, NE quadrant of Steep Gully quadrangle, Louisiana, UTM 15 NAD83, Louisiana Federal Emergency Management Agency (FEMA)Rapides Parish, Louisiana under the Watershed Concepts contract number EMT-2002-CO-0048, Task Order 013. [bsh_3009202ne].

   Type_of_Source_Media: computer file

   Source_Contribution: Hydrography breaklines

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

   Date: 2003 (process 1 of 2)

   SCP_3009202ne and BHY_DSET_NAME were loaded into TerraModeler, and used to produce a TIN surface model that was contoured. The contours were edited as necessary to repair contour line crossings, clipped to a 3.75 minute tile size, then edgematched to adjacent tiles. A DXF export of the contour lines was converted to an ArcInfo line coverage.

   Person who carried out this activity:
   

   3001, Inc.
   LIDAR Manager
   5525 Mounes, Suite 102
   New Orleans, LA 70123
   

   (504) 733-3001 (voice)
   

   (process 2 of 2)

   Metadata imported.

   Data sources used in this process:

   • L:\Task13\metadata\Template\contour_template.xml

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

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?

   Depression contours have not been identified. Contour lines enclosing areas smaller than 25 square meters have been eliminated.

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

   The contour data have been edgematched to adjacent tiles in this project and automated testing has revealed that no contour lines cross others. The data exhibit spikes and on slopes and banks that are the result of trees and bushes that were not effectively filtered out of precursor source data. Pockets of trees result in complex areas of contouring that represent vegetation noise rather than any real variation in bare ground surface.

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

Access_Constraints: none

Use_Constraints:

These unaltered data may not be redistributed without all of the elements of the metadata listed in the Supplemental_Information section of this metadata document.

Dates:

Last modified: 20-Jun-2003

Metadata author:

3001, Inc.
5525 Mounes Street, Suite 102
New Orleans, LA 70123

(504) 733-3001 (voice)
(504) 733-8938 (FAX)

Metadata standard:

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