U.S. Geological Survey 2007 vector digital data Reston, VA U.S. Geological Survey http://water.usgs.gov/lookup/getspatial?ofr07-1056_up_diff_tin Ryan F. Thompson Michaela R. Johnson Michael J. Anderson 2007 U.S. Geological Survey Scientific Investigations Report 2007-1056 Reston, VA U.S. Geological Survey http://pubs.usgs.gov/of/2007/1056/ This geospatial data set contains an interpolated 3-D surface or, triangulated-irregular network (TIN), of the change in elevation, in feet, of the substrate between cross-sections 22 and 35 following construction of Emergent Sandbar Habitat near River Mile 770. The surface was generated from points collected by the echosounder and real-time kinematic (RTK) GPS on cross-sections in the downstream project reach surrounding the construction area at River Mile 770 below Gavins Point Dam on the Missouri River in South Dakota before and after construction of the sandbar. The purpose of this dataset is to visualize the change in channel substrate configuration interpolated from the data collected near RM 770 before and after construction of the sandbar. 200602 ground condition Complete Unknown -96.876334 -96.851104 42.732505 42.712792 None inlandWaters Hydrographic Survey None Missouri River below Gavins Point Dam none The Missouri River is a rapidly changing system. These data should not be used for vessel navigation. U.S. Geological Survey Ryan F. Thompson Hydrologist mailing and physical address

111 Kansas Ave SE

Huron SD 57324 605 352-4241 x225 rcthomps@usgs.gov Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.1.0.722 The Innerspace Technologies dual-frequency 456 echosounder was calibrated twice daily with bar checks. Vessel draft was measured with each bar check and was used to calculated water depth. A CSI Wireless, Omnistar corrected differential GPS antenna mounted directly above the echosounder was used to collect the horizontal location of each depth measurement. RTK GPS was used to measure water surface elevation at each transect, which was then used to calculate elevation of the channel bottom. Conversion to NGVD29 vertical datum was completed so that the data could be compared to existing COE benchmarks and gaging station data. The datum conversion was accomplished using the National Geodetic Survey's VERTCON program (http://www.ngs.noaa.gov/cgi-bin/VERTCON/vert_con.prl). Topologically correct The datasets on which this tin are based were checked and attributed. Source data for this tin are bathymetry data and RTK GPS (topography) data. Data sets werecollected in UTM NAD83 Zone 14 meters. Some preliminary editing was completed in Hypack by deleting bad data points. 200411 Edited data was exported from hypack and used to create an ArcGIS Shapefile. RTK GPS data was exported as a text file and used to create an ArcGIS Shapefile. 2005 Attribute fields were added and populated. Additional bad data points were deleted as necessary. 2005 Data was projected to UTM Zone 14, with units of US feet. The elevation datum was converted from NAVD88 to NGVD29. 2005 Pre-construction and post-construction RTK GPS and bathymetric data points were reduced to a subset of cross-sections; 22 to 35. The additional cross-sections surveyed post-construction were excluded in this analysis. The GPS and bathymetric datasets were combined for each time period sampled. Then pre-construction data were spatially joined to the post-construction data when the minimum distance to the nearest post-construction data point collected was 2 meters or less. The pre-construction elevation was subtracted from the post-construction elevation. A positive value indicated a loss in substrate and a negative value indicated a gain in substrate for the substrate from pre- to post-construction . A clip polygon shapefile was generated to confine the area at or below top of bank and within the selected cross-sections. A TIN was created from the change in elevation data as mass points. The polygon clip dataset was used as an additional input when the TIN was generated to keep only the area within the selected cross-sections and below the top of bank. 20061204 Vector Ring composed of chains 43248 Node, planar graph 22088 Link 129744 Transverse Mercator 0.999600 -99.000000 0.000000 1640416.666667 0.000000 coordinate pair 0.000004 0.000004 survey feet North American Datum of 1983 Geodetic Reference System 80 6378137.000000 298.257222 National Geodetic Vertical Datum of 1929 0.1 Feet Explicit elevation coordinate included with horizontal coordinates Mean sea level 0.1 feet Explicit depth coordinate included with horizontal coordinates Elevations on which this dataset are based are composed of bathymetry and RTK GPS data points, and are expressed in NGVD29. For additional details concerning the study for which these data were collected, see online OFR 2007-1056. U.S. Geological Survey Ask USGS -- Water Webserver Team mailing address

445 National Center

Reston VA 20192 USA 1-888-275-8747 (1-888-ASK-USGS) http://answers.usgs.gov/cgi-bin/gsanswers?pemail=h2oteam&subject=GIS+Dataset+ofr041189it03 Downloadable Data The South Dakota and Nebraska Water Science Centers, the Water Resources Discipline (WRD) of the U.S. Geological Survey, and the U.S. Army Corps of Engineers make no guarantee nor offer any warranty concerning the accuracy, condition, or application of the information contained in these geographic data. The burden for determining fitness for use of this data lies entirely with the user. Although these data have been used successfully on computers of WRD, no warranty, expressed or implied, is made by WRD regarding the use of these data on any other system, nor does the fact of distribution constitute or imply any such warranty. In no event shall the WRD have any liability whatsoever for payment of any consequential, incidental, indirect, special, or tort damages of any kind, including , but not limited to, any loss of profits arising out of the delivery, installation, operation, or support by WRD. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. ARCE 1.499 http://water.usgs.gov/GIS/dsdl/up_diff_tin.zip None 20070306 U.S. Geological Survey Ask USGS -- Water Webserver Team mailing address

445 National Center

Reston VA 20192 USA 1-888-275-8747 (1-888-ASK-USGS) http://answers.usgs.gov/cgi-bin/gsanswers?pemail=h2oteam&subject=GIS+Dataset+ofr07-1056_up_diff_tin.shp FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998