Interpretation of Sidescan-sonar Imagery in the John Day Reservoir

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• 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?
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  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?
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• How was the data set created?
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  3. How accurate are the heights or depths?
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Title:

Interpretation of Sidescan-sonar Imagery in the John Day Reservoir

Abstract:

A two-week field operation was conducted in the John Day Reservoir on the Columbia River to image the floor of the pool, to measure the distribution and thickness of post-impoundment sediment, and to verify these geophysical data with video photography and bottom sediment samples. The field program was a cooperative effort between the USGS Coastal and Marine Geology Team of the Geologic Division and the USGS Columbia River Research Laboratory of the Biological Resources Division. The data collection was completed aboard the R/V ESTERO during September 13-27, 2000. The interest in sediment accumulation in the reservoir was two-fold. First, it was unknown how effective this reservoir was as a sediment trap to material that otherwise would have been transported down-river to the estuary and eventually to the ocean. The recent erosion of beaches along the Washington coast has been attributed to a decreased contribution of sediment from the Columbia River to the coastal system due to the damming of the river. Second, sediment accumulation on the floors of reservoirs along the Columbia River has been suggested to be diminishing salmon spawning grounds. The extent of changes in habitat since construction of the John Day Dam, however, had not been documented. Common data sets were needed to address both of these questions, and for these reasons this geophysical and sampling program was undertaken.

1. How should this data set be cited?

   Twichell, David C. , 2004, Interpretation of Sidescan-sonar Imagery in the John Day Reservoir:.

   Online Links:

   This is part of the following larger work.

   Cross, VeeAnn A. , and Twichell, David C. , 2004, Geophysical, Sedimentologic, and Photographic Data from the John Day Reservoir, Washington and Oregon: Data Archive and Preliminary Discussion: Open-File Report 2004-1014, U.S. Geological Survey, Woods Hole Science Center, Woods Hole, MA.

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -120.683233

   East_Bounding_Coordinate: -119.327509

   North_Bounding_Coordinate: 45.934511

   South_Bounding_Coordinate: 45.687974

3. What does it look like?

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

   Beginning_Date: 11-Sep-2000

   Ending_Date: 22-Sep-2000

   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):

      • G-polygon (195)

   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 0.000000. Longitudes are given to the nearest 0.000000. Latitude and longitude values are specified in Decimal degrees.

      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 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257222.
      

7. How does the data set describe geographic features?

   ss_interpretation

   FID

   Internal feature number. (Source: ESRI)

   Sequential unique whole numbers that are automatically generated.

   Shape

   Feature geometry. (Source: ESRI)

   Coordinates defining the features.

   ID

   Automatically generated number during feature creation. (Source: Software generated.)

   BACKSCAT

   Indicator of backscatter intensity. (Source: Scientist.)

   character set

   INTERP

   Interpretation of what is present on the floor of the John Day Reservoir based on the sidescan-sonar imagery. (Source: Scientist.)

   character set

   TIMING

   Indication of whether the interpreted feature was developed pre- or post-impoundment (formation of the John Day Reservoir). (Source: Scientist.)

   character set

   DEP_TYPE

   Indicates whether the interpreted feature is basement, fluvially generated deposit, post-impoundment sand, or post-impoundment mud. (Source: Scientist.)

   character set

   AREA

   Area (square meters calculated using Washington State Plane South, NAD83 projection) of each individual polygon. (Source: Software generated.)

   Range of values
   Minimum:	3490.246
   Maximum:	14770057.024
   Units:	square meters

   PERIMETER

   Perimeter (meters calculated using Washington State Plane South, NAD83 projection) of each individual polygon. (Source: Scientist.)

   Range of values
   Minimum:	230.701
   Maximum:	104394.129
   Units:	meters

   Entity_and_Attribute_Overview:

   Dep_type contains Miocene, Quaternary, and boulders. The boulders are believed to be deposited as a result of the Missoula floods, so the argument could be made that these are fluvial deposits. However, in this case, fluvial deposits refers to more modern deposits formed as a result of the Columbia River pre-impoundment. The Area and Perimeter calculations were done in ArcView 3.3 using the sample script calcapl.ave. The view projection was defined as Washington State Plane South, NAD83 in order to have the units in meters and be consistent with the projected sidescan-sonar imagery.

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

2. Who also contributed to the data set?

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

   David C. Twichell
   U.S. Geological Survey
   Oceanographer
   384 Woods Hole Rd.
   Woods Hole, MA 02543-1598
   

   (508) 548-8700 x2266 (voice)
   (508) 457-2310 (FAX)
   dtwichell@usgs.gov
   

This shapefile is intended to provide an interpretation of the sidescan-sonar imagery collected in the John Day Reservoir.

1. From what previous works were the data drawn?

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

   (process 1 of 1)

   Using the mosaicked sidescan-sonar imagery as a backdrop, polygons were digitized in ArcView 3.3 representing different interpreted areas.

   Person who carried out this activity:
   

   David C. Twichell
   U.S. Geological Survey
   Oceanographer
   384 Woods Hole Rd.
   Woods Hole, MA 02543-1598
   

   (508) 548-8700 x2266 (voice)
   (508) 457-2310 (FAX)
   dtwichell@usgs.gov
   

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 observations, including topology?

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

Access_Constraints: None.

Use_Constraints:

The U.S. Geological Survey must be referenced as the originator of the dataset in any future products or research derived from these data.

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

   David C. Twichell
   U.S. Geological Survey
   Oceanographer
   384 Woods Hole Rd.
   Woods Hole, MA 02543-1598
   

   (508) 548-8700 x2266 (voice)
   (508) 457-2310 (FAX)
   dtwichell@usgs.gov
   

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

   Downloadable Data

3. What legal disclaimers am I supposed to read?

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

     Data format:	shapefile Size: 0.259

   • Cost to order the data:

Dates:

Last modified: 25-Mar-2004

Metadata author:

VeeAnn A. Cross
U.S. Geological Survey
Marine Geologist
384 Woods Hole Rd.
Woods Hole, MA 02543-1598

(508) 548-8700 x2251 (voice)
(508) 457-2310 (FAX)
vatnipp@usgs.gov

Metadata standard:

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

Metadata extensions used:

• <http://www.esri.com/metadata/esriprof80.html>