Hillshade Surface Representing the Floor of Lake Mead and the surrounding area: Geographic Coordinates 30m cellsize TIFF format

Metadata also available as - [Questions & Answers] - [Parseable text]

Metadata:
Identification_Information:
Citation:
Citation_Information:
Originator: Stephen D. Belew
Originator: VeeAnn A. Cross
Publication_Date: 2003
Title:
Hillshade Surface Representing the Floor of Lake Mead and the surrounding area: Geographic Coordinates 30m cellsize TIFF format
Geospatial_Data_Presentation_Form: remote-sensing image
Online_Linkage:
Larger_Work_Citation:
Citation_Information:
Originator: David C. Twichell
Originator: VeeAnn A. Cross
Originator: Stephen D. Belew
Publication_Date: 2003
Title:
Mapping the floor of Lake Mead (Nevada and Arizona): Preliminary discussion and GIS data release
Edition: 1.0
Series_Information:
Series_Name: Open-File Report
Issue_Identification: 03-320
Publication_Information:
Publication_Place: Woods Hole Field Center, Woods Hole, MA
Publisher: U.S. Geological Survey
Description:
Abstract:
Lake Mead is a large interstate reservoir located in the Mojave Desert of southeastern Nevada and northwestern Arizona. It was impounded in 1935 by the construction of Hoover Dam and is one of a series of multi-purpose reservoirs on the Colorado River. The lake extends 183 km from the mouth of the Grand Canyon to Black Canyon, the site of Hoover Dam, and provides water for residential, commercial, industrial, recreational, and other non-agricultural users in communities across the southwestern United States. Extensive research has been conducted on Lake Mead, but a majority of the studies have involved determining levels of anthropogenic contaminants such as synthetic organic compounds, heavy metals and dissolved ions, furans/dioxins, and nutrient loading in lake water, sediment, and biota (Preissler, et al., 1998; Bevans et al, 1996; Bevans et al., 1998; Covay and Leiker, 1998; LaBounty and Horn, 1997; Paulson, 1981). By contrast, little work has focused on the sediments in the lake and the processes of deposition (Gould, 1951). To address these questions, sidescan-sonar imagery and high-resolution seismic-reflection profiles were collected throughout Lake Mead by the USGS in cooperation with researchers from University of Nevada Las Vegas (UNLV). These data allow a detailed mapping of the surficial geology and the distribution and thickness of sediment that has accumulated in the lake since the completion of Hoover Dam. Results indicate that the accumulation of post-impoundment sediment is primarily restricted to former river and stream beds that are now submerged below the lake while the margins of the lake appear to be devoid of post-impoundment sediment. The sediment cover along the original Colorado River bed is continuous and is typically greater than 10 m thick through much of its length. Sediment thickness in some areas exceeds 35 m while the smaller tributary valleys typically are filled with less than 4 m of sediment. Away from the river beds that are now covered with post-impoundment sediment, pre-impoundment alluvial deposits and rock outcrops are still exposed on the lake floor.
Purpose:
This GIS (ESRI) grid represents the integration swath bathymetry, on land DEM, and underwater surface derived from countour maps generated pre-impoundment.
Supplemental_Information:
Questions regarding the swath bathymetry portion of this dataset should be directed to Steve Belew, while questions regarding the remainder of the dataset and the integration should be directed to VeeAnn Cross.
Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 19300000
Ending_Date: 20011100
Currentness_Reference: ground condition
Status:
Progress: Complete
Maintenance_and_Update_Frequency: None planned
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -114.996605
East_Bounding_Coordinate: -114.003443
North_Bounding_Coordinate: 36.747104
South_Bounding_Coordinate: 35.758151
Keywords:
Theme:
Theme_Keyword_Thesaurus: General
Theme_Keyword: ArcView
Theme_Keyword: bathymetry
Theme_Keyword: CMGP
Theme_Keyword: Coastal and Marine Geology Program
Theme_Keyword: DEM
Theme_Keyword: digital elevation model
Theme_Keyword: grid
Theme_Keyword: images
Theme_Keyword: lake
Theme_Keyword: mosaic
Theme_Keyword: OFR03-320
Theme_Keyword: Open-File Report
Theme_Keyword: reservoir
Theme_Keyword: U.S. Geological Survey
Theme_Keyword: USGS
Theme_Keyword: Woods Hole Field Center
Theme_Keyword: TIFF
Theme_Keyword: Bureau of Reclamation
Place:
Place_Keyword_Thesaurus: General
Place_Keyword: Arizona
Place_Keyword: Black Canyon
Place_Keyword: Boulder Basin
Place_Keyword: Colorado River
Place_Keyword: Gregg Basin
Place_Keyword: Hoover Dam
Place_Keyword: Iceberg Canyon
Place_Keyword: Lake Mead
Place_Keyword: Las Vegas
Place_Keyword: Las Vegas Bay
Place_Keyword: Las Vegas Wash
Place_Keyword: Mohave Desert
Place_Keyword: Nevada
Place_Keyword: Overton Arm
Place_Keyword: United States
Place_Keyword: Virgin Basin
Place_Keyword: North America
Access_Constraints: NONE
Use_Constraints:
The U.S. Geological Survey and Bureau of Reclamation must be referenced as the originator of the dataset in any future products or research derived from these data.
Point_of_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Steve Belew
Contact_Organization: Bureau of Reclamation
Contact_Position: GIS Specialist
Contact_Address:
Address_Type: mailing address
Address: P.O. Box 61470
City: Boulder City
State_or_Province: NV
Postal_Code: 89006-1470
Country: sbelew@usbr.gov
Contact_Voice_Telephone: (702) 293-8150
Native_Data_Set_Environment:
Microsoft Windows 2000 Version 5.0 (Build 2195) Service Pack 4; ESRI ArcCatalog 8.2.0.700
Cross_Reference:
Citation_Information:
Originator: H.E. Bevans
Originator: S.L. Goodbred
Originator: J.F. Miesner
Originator: S.A. Watkins
Originator: T.S. Gross
Originator: N.D. Denslow
Originator: T. Choeb
Publication_Date: 1996
Title:
Synthetic organic compounds and carp endrocrinology and histology, Las Vegas Wash and Las Vegas and Callville bays of Lake Mead Nevada
Series_Information:
Series_Name: Water-Resources Investigations
Issue_Identification: 96-4266
Publication_Information:
Publisher: U.S. Geological Survey
Cross_Reference:
Citation_Information:
Originator: H.E. Bevans
Originator: M.S. Lico
Originator: S.J. Lawrence
Publication_Date: 1998
Title:
Water quality in the Las Vegas Valley area and the Carson and Truckee River basins, Nevada and California, 1992-1996
Series_Information:
Series_Name: Circular
Issue_Identification: 1170
Publication_Information:
Publisher: U.S. Geological Survey
Cross_Reference:
Citation_Information:
Originator: K.J. Couvay
Originator: T.J. Leiker
Publication_Date: 1998
Title:
Synthetic organic compounds in water and bottom sediment from streams, detention basins, and sewage-treatment plant outfalls in Las Vegas Valley, Nevada, 1997
Series_Information:
Series_Name: Open-File Report
Issue_Identification: 98-633
Publication_Information:
Publisher: U.S. Geological Survey
Cross_Reference:
Citation_Information:
Originator: H.R. Gould
Publication_Date: 1951
Title: Some quantitative aspects of Lake Mead turbidity currents
Series_Information:
Series_Name: SEPM Special Publication
Issue_Identification: No. 2
Publication_Information:
Publisher: Society of Economic Paleontologists and Mineralogists
Cross_Reference:
Citation_Information:
Originator: J.F. LaBounty
Originator: M.J. Horn
Publication_Date: 1997
Title:
The influence of drainage from the Las Vegas Valley on the limnology of Boulder Basin, Lake Mead, Arizona-Nevada
Series_Information:
Series_Name: Journal of Lake and Reservoir Management
Issue_Identification: v. 13
Cross_Reference:
Citation_Information:
Originator: L.J. Paulson
Publication_Date: 1981
Title:
Nutrient management with hydroelectric dams on the Colorado River
Series_Information:
Series_Name: Technical Report
Issue_Identification: #8
Publication_Information:
Publication_Place:
Department of Biological Sciences, University of Nevada, Las Vegas, Nevada
Publisher: Lake Mead Limnological Research Center
Cross_Reference:
Citation_Information:
Originator: A.M. Preissler
Originator: G.A. Roach
Originator: K.A. Thomas
Originator: J.W. Wilson
Publication_Date: 1998
Title: Water resources data, Nevada, water year 1998
Series_Information:
Series_Name: Water Resources Data Nevada
Issue_Identification: NV-98-1
Publication_Information:
Publisher: U.S. Geological Survey
Data_Quality_Information:
Attribute_Accuracy:
Attribute_Accuracy_Report:
The nature of combining three different datasets tends to reduce the overall accuracy. Therefore a nominal accuracy of 50-100m is assigned to this dataset.
Logical_Consistency_Report:
This surface represents the integration of three datasets. One is the swath bathymetry data collected in Lake Mead in November of 2001. The second dataset is the on land DEM acquired from the NED (National Elevation Dataset) project. And the final dataset is the surface generated from pre-impoundment elevation contours as digitized from DRG's of Lake Mead (digital raster graphics). Due to the nature of combining these three different datasets, discrepancies are evident at the bounds of each of the datasets.
Completeness_Report: This dataset is complete.
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Quantitative_Horizontal_Positional_Accuracy_Assessment:
Vertical_Positional_Accuracy:
Quantitative_Vertical_Positional_Accuracy_Assessment:
Lineage:
Process_Step:
Process_Description:
Three sets of data were acquired. The DEM from the area surrounding Lake Mead was acquired from NED (National Elevation Dataset) in 1998. This data was available as 30m/pixel. The swath bathymetry data was collected in Lake Mead during the fall of 2001. Bureau of Reclamation had this data at a very high resolution. The area covered by this surveying is effectively limited to the areas of post-impoundment sediment. The underwater contours available from the DRG's (digital raster graphics) were digitized. These contours were then used to create an underwater surface using the ESRI topogrid command available in Arc/Info. This surface was created with a 10 m/pixel resolution.
Process_Step:
Process_Description:
The lake bounds shapefile was used to clip the DEM dataset such that all values falling within the lake bounds were turned to NODATA values.
Process_Step:
Process_Description:
The lake bounds shapefile was used to clip the topogrid dataset such that all values falling outside the lake bounds were turned to NODATA values.
Process_Step:
Process_Description:
The high-resolution bathymetry data was resampled to a 10 m cellsize using bilinear interpolation.
Process_Step:
Process_Description:
The swath bathymetry grid was merged with the topogrid surface such that where swath bathymetry data was available, the topogrid surface was overwritten. This provided the present day lakefloor of Lake Mead.
Process_Step:
Process_Description:
The on land DEM was resampled to a 10 m cellsize grid (super sampling).
Process_Step:
Process_Description:
This supersampled on land DEM was then combined with the lake floor surface.
Process_Step:
Process_Description:
The resulting surface then underwent several repetitions of a 4x4 focal mean filtering to remove and null data values and to smooth the transition from one dataset to the next.
Process_Step:
Process_Description: The surface was then resampled to a 30m cellsize.
Process_Step:
Process_Description:
This grid surface was then used to generate a hillshade relief image in ArcMap using the default settings.
Process_Step:
Process_Description:
The ArcInfo command gridimage was used to convert the hillshade grid to a TIFF image.
Process_Step:
Process_Description:
This TIFF image was then brought into Corel PhotoPaint, version 11, and converted to an 8-bit paletted image and saved with PackBit compression.
Process_Step:
Process_Description:
This image was then reprojected to the geographic coordinate system using BlueMarble's geographic transformer software. Used a central latitude of 36N.
Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method: Raster
Raster_Object_Information:
Raster_Object_Type: Pixel
Row_Count: 3657
Column_Count: 2971
Vertical_Count: 1
Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Geographic:
Latitude_Resolution: 0.000270
Longitude_Resolution: 0.000334
Geographic_Coordinate_Units: Decimal degrees
Planar:
Planar_Coordinate_Information:
Planar_Coordinate_Encoding_Method: row and column
Coordinate_Representation:
Abscissa_Resolution: 0.000334
Ordinate_Resolution: 0.000270
Geodetic_Model:
Horizontal_Datum_Name: North American Datum of 1983
Ellipsoid_Name: Geodetic Reference System 80
Semi-major_Axis: 6378137.000000
Denominator_of_Flattening_Ratio: 298.257222
Entity_and_Attribute_Information:
Detailed_Description:
Entity_Type:
Entity_Type_Label: Band_1
Attribute:
Attribute_Label: ObjectID
Attribute_Definition: Internal feature number.
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
Unrepresentable_Domain:
Sequential unique whole numbers that are automatically generated.
Attribute:
Attribute_Label: Value
Attribute:
Attribute_Label: Red
Attribute:
Attribute_Label: Green
Attribute:
Attribute_Label: Blue
Distribution_Information:
Distributor:
Contact_Information:
Contact_Person_Primary:
Contact_Person: VeeAnn A. Cross
Contact_Organization: U.S. Geological Survey
Contact_Position: Marine Geologist
Contact_Address:
Address_Type: mailing and physical address
Address: 384 Woods Hole Rd.
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543-1598
Contact_Voice_Telephone: (508) 548-8700 x2251
Contact_Facsimile_Telephone: (508) 457-2310
Contact_Electronic_Mail_Address: vatnipp@usgs.gov
Resource_Description: Downloadable Data
Distribution_Liability:
These data were prepared by an agency of the United States Government. Neither the United States government nor any agency thereof, nor any of their employees, make any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed in this report, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States government or any agency thereof. Any views and opinions of authors expressed herein do not necessarily state or reflect those of the United States government or any agency thereof. Although all data published in this report have been used by the USGS, no warranty, expressed or implied, is made by the USGS as to the accuracy of the data and related materials and/or the functioning of the software. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of this data, software, or related materials.
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Transfer_Size: 9.567
Metadata_Reference_Information:
Metadata_Date: 20031006
Metadata_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: VeeAnn A. Cross
Contact_Organization: U.S. Geological Survey
Contact_Position: Marine Geologist
Contact_Address:
Address_Type: mailing and physical address
Address: 384 Woods Hole Rd.
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543-1598
Contact_Voice_Telephone: (508) 548-8700 x2251
Contact_Facsimile_Telephone: (508) 457-2310
Contact_Electronic_Mail_Address: vatnipp@usgs.gov
Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998
Metadata_Time_Convention: local time
Metadata_Extensions:
Online_Linkage: <http://www.esri.com/metadata/esriprof80.html>
Profile_Name: ESRI Metadata Profile
Generated by mp version 2.7.3 on Mon Oct 06 12:37:01 2003