This digital geospatial data set consists of depth-to-water (unsaturated-thickness) contours that were generated with a Geographic Information System (GIS). The U.S. Geological Survey developed this data set as part of a project that is presented in the report, Geohydrology of the shallow aquifers in the Denver metropolitan area, Colorado (Robson, 1996).
This data set was created by the U.S. Geological Survey (USGS) in the development of USGS Hydrologic Investigations Atlas HA-736 (Robson, 1996). This data set was used to create a 1:50,000-scale map.
Procedures_Used Using Arc/INFO software, USGS 7.5-minute Digital Elevation Models (DEMs) that encompass the study area were converted to raster surface formats (grids, in ARC/INFO terminology) with the command, DEMLATTICE. They were mosaicked into a single continuous surface with the Arc/INFO GRID command, MERGE, and projected into an appropriate coordinate system using the command, PROJECT. The grid was then smoothed using an averaging filter with a radius of 9 grid cells (180 meters): Grid: lsdcir9 = focalmean (all_lsd7spc,circle,9,data) A contour data set (coverage, in ARC/INFO terminology) of water- table altitude (documented separately) was converted to a grid with the same cell size as the DEM-derived data (approximately 30-meter spacing between data points). Arc:createtin wttin3 30 30 All Rights Reserved Worldwide. CREATETIN Version 6.1.1(December 23, 1992) Createtin:cover watertable2 line contour 1 Createtin:cover wtpts point contour 1 Createtin:end Loading arcs from coverage watertable2... Weed tolerance 30.000, input arc points 182669,remaining 62545... Loading points from coverage wtpts... Proximal tolerance set to 30.000... Removing points within tolerance... Within tolerance 12943. Remaining 49679... Creating TIN... Writing TIN data structures... Arc:tinlattice wttin3 wtgrd3 quintic Converting tin wttin3 to quintic lattice wtgrd3... TIN boundary Xmin = 630971.000Ymin = 192412.063 Xmax = 676910.625Ymax = 240848.578 X-extent= 45939.625Y-extent= 48436.516 Lattice parameter input ------------------------ Enter lattice origin :630910.800 185004.800 Enter lattice upper-right corner :684848.000 240905.000 Enter lattice resolution : Enter distance between lattice mesh points :30.2 Lattice has 1786 points in x, 1852 points in y... Spacing between mesh points (d) is (30.200)... Loading TIN data structures... Loading TIN data structures...Initializing interpolation... Arc: The water-table-altitude grid was subtracted from the land-surface- altitude grid to produce a depth-to-water grid. Grid: uszgrd5 = /gis/arcwork/temparc/shaqdems/lsdcir9 - ../watertable/wtgrd3 The depth-to-water grid was processed to remove values less than -20 feet and greater than or equal to 1,000 feet. Using the depth-to-water grid, the software generated contours at an interval of 20 feet to produce the contour coverage of depth to water. Grid: uszgrd5b = select (uszgrd5, value ge -20 and value lt 1000) Arc: latticecontour uszgrd5b uszcnt5b 20 0 # 20 Manual editing corrected contours that were not correctly inter- polated, as determined by consultation with the projects author. The coverage was built with line topology and clipped with a coverage of the study area outline. Arc: clip uszcnt5b1 ../watertable/usz_clipper uszcnt5b1cp line 2.5 The jagged appearance of the contours was addressed by smoothing the contours in an editing session. Arc vertex grain tolerances (the minimum allowable distance between vertices in a line) were set to 90 meters, all the arcs were generalized with the Arcedit command, SPLINE, and the grain tolerances were reset to 30 meters before splining the arcs again. Arc items "CNT_INT," "TEXTKEY," and "DEPRESSION" were added to the coverage arc attribute table for plotting purposes. Further editing defined how the arcs would be displayed in a plotting routine. Also, arc items "TEXTKEY" and "DEPRESSION" were attributed in this editing session. Hardcopy and base map overlays were used for reference. The final coverage is intended to be used as one thematic layer in maps to be published at a scale of 1:50,000. Revisions Rev 1.0, 4/17/96, original data set. Reviews_Applied July-August 1994: Colleague review of 1:50,000-scale maps that were generated from the original data set. Manuscript review included validation of method as outlined in map report and inspection for positional accuracy. January-Febuary 1996: Colleague review of original digital data set and associated metadata. Metadata review included verification of table and column/item identities and definitions, validation of the reference data sets and citations, verification of consistency between log file and documented procedures, and validation of development method as described in the documentation. March 1996: Inspection of 1:50,000-scale hardcopy generated from this data set. Related_Spatial_and_Tabular_Data_Sets None. Other_References_Cited Robson, S.G., 1996, Geohydrology of the shallow aquifers in the Denver metropolitan area, Colorado: U.S. Geological Survey Hydrologic Investigations Atlas HA-736, 5 sheets, scale 1:50,000. Notes Char, Stephen J., Sieverling, Jennifer B., and Miller, L. Lee, 1996, Digital geospatial data sets used in the study of geohydrology of the shallow aquifers in the Denver metro- politan area, Colorado: a)Bedrock outcrop, b)Unconsolidated- sediment thickness, c)Water-table altitude, d)Bedrock- surface altitude, e)Depth to water, and f)Saturated-zone thickness: U.S. Geological Survey Open-File Report 96-659. Any use of trade, product or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this metadata file is designed to conform to the Federal Geographic Data Committee Spatial Metadata Content Standard, these data and this metadata file were developed using ARC/INFO software; therefore, this file includes ARC/INFO-specific terminology. Data used to develop this project were obtained from many sources, including the following: Cherry Creek Valley Water and Sanitation District City of Brighton Colorado Department of Health Colorado Department of Highways Colorado State Engineers Office Cooley Sand and Gravel Denver Federal Center Denver Water Department EG&G Rocky Flats Incorporated Environmental Protection Agency (Superfund) Frei & Sons (Sand and Gravel) HRS Consultants Lowry Air Force Base Metro Denver Wastewater Reclamation District Public Service Company Rocky Mountain Arsenal U.S. Army Corps of Engineers Urban Drainage and Flood Control Western Mobile Incorporated
publication date
This data set should not be used at a scale larger than 1:50,000.
Box 25046, MS 415, Denver Federal Center
U.S. Army--Rocky Mountain Arsenal U.S. Department of Energy--Rocky Flats Field Office Colorado Department of Public Health and Environment Colorado Department of Natural Resources--State Engineers Office Denver Water Department Littleton-Englewood Wastewater Treatment Plant East Cherry Creek Valley Water and Sanitation District Metro Wastewater Reclamation District Willows Water District Cities of Aurora, Lakewood, and Thornton
See Entity_Attribute_Information
attribute defined in the Entity and Attribute Section
Chain-node topology present.
The DEM-derived input data set was smoothed with a circular filter of a 9-cell-length (180-meter) radius. After the data set was smoothed, it matched more closely the apparent resolution of the water-table data set. The final depth-to-water contour data set would have been too convolute (implying more detail than was supportable by the water-table data set) if it had been produced using an unfiltered DEM-derived data set. The contours that comprise one of the input data sets (watertable2) were digitized by hand at a scale of 1:24,000 from hand-drawn maps. The hand-drawn contours for watertable2 were interpolated at 20-foot intervals using data from wells whose locations were reported in Public Land Survey System coordinates. The well locations are theoretically accurate to the nearest quarter-quarter-quarter-quarter section, but they were not field-checked for accuracy. The limited number of supplemental hand-drawn points that comprise wtpts were interpolated at various intervals, generally 5-foot intervals, from the same well data. The supplemental points were intended to enhance the surface interpolation in areas of the South Platte River Valley where the CREATETIN session failed to accurately represent the water-table surface.
The DEM-derived input data set was smoothed with a circular filter of a 9-cell-length (180-meter) radius. After the data set was smoothed, it matched more closely the apparent resolution of the water-table data set. The final depth-to-water contour data set would have been too convolute (implying more detail than was supportable by the water-table data set) if it had been produced using an unfiltered DEM-derived data set. The contours that comprise one of the input data sets (watertable2) were digitized by hand at a scale of 1:24,000 from hand-drawn maps. The hand-drawn contours for watertable2 were interpolated at 20-foot intervals using data from wells whose locations were reported in Public Land Survey System coordinates. The well locations are theoretically accurate to the nearest quarter-quarter-quarter-quarter section, but they were not field-checked for accuracy. The limited number of supplemental hand-drawn points that comprise wtpts were interpolated at various intervals, generally 5-foot intervals, from the same well data. The supplemental points were intended to enhance the surface interpolation in areas of the South Platte River Valley where the CREATETIN session failed to accurately represent the water-table surface.
LATTICECONTOUR USZGRD5B USZCNT5B 20 0 # 20
ARCEDIT USZCNT5B1
ARCEDIT /GIS/USERS/ROBSON/UNSATZN/USZCNT5B1
CLIP USZCNT5B1 ../WATERTABLE/USZ_CLIPPER USZCNT5B1CP LINE 2.5
ARCEDIT /GIS/USERS/ROBSON/UNSATZN/USZCNT5B1CP
ARCEDIT UNSAT
ARCEDIT /GIS/USERS/ROBSON/UNSATZN/UNSAT
ARCEDIT /GIS/USERS/ROBSON/UNSATZN/UNSAT
ARCEDIT /GIS/USERS/ROBSON/UNSATZN/UNSAT
RESTOREARCEDIT UNSAT
ARCEDIT /GIS/USERS/ROBSON/UNSATZN/UNSAT
ARCEDIT /GIS/USERS/ROBSON/UNSATZN/UNSAT
ARCEDIT UNSAT_SM
DOCUMENT UNSAT_SM CREATE SJCHAR
COPY UNSATZN/UNSAT_SM FINALS/UNSATZN
DOCUMENT UNSATZN UPDATE SJCHAR
DOCUMENT UNSATZN UPDATE SJCHAR
DOCUMENT UNSATZN UPDATE SJCHAR
BUILD UNSATZN LINE
DOCUMENT UNSATZN UPDATE SJCHAR
EXPORT COVER UNSATZN UNSATZN
COPY ../FINALS/UNSATZN UNSATZN
ARCEDIT UNSATZN_F1
ARCEDIT /GIS/USERS/ROBSON/UNSATZN/UNSATZN_F1
BUILD UNSATZN_F1 LINE
COPY UNSATZN_F1 /GIS/USERS/ROBSON/FINALS/UNSATZN_F1
DOCUMENT UNSATZN_F1 UPDATE SJCHAR
EXPORT COVER UNSATZN_F1 UNSATZN_F1
COPY /GIS/USERS/ROBSON/FINALS/UNSATZN_F1
COPY UNSATZN_F1 /WORK/GTI1WORK/SARAFFER/EXPORT/UNSATZN_F1
JMWATER ARCEDIT /PROJ/MISC/JOHN_COHELP/EXPORT/UNSATZN_F1
JMWATER ARCEDIT /PROJ/MISC/JOHN_COHELP/EXPORT/UNSATZN_F1
SARAFFER ARCEDIT /HOME/GTI1WORK/SARAFFER/CAPP/JOHN_COHELP/EXPORT/UNSATZN_F1
SARAFFER COPY UNSATZN_F1 UNSATZNNEW_F1
SARAFFER ARCEDIT /HOME/GTI1WORK/SARAFFER/CAPP/JOHN_COHELP/EXPORT/UNSATZNNEW_F1
SARAFFER BUILD UNSATZNNEW_F1 LINE
SARAFFER ARCEDIT /HOME/GTI1WORK/SARAFFER/CAPP/JOHN_COHELP/EXPORT/UNSATZNNEW_F1
SARAFFER ARCEDIT /HOME/GTI1WORK/SARAFFER/CAPP/JOHN_COHELP/EXPORT/UNSATZNNEW_F1
SARAFFER BUILD UNSATZNNEW_F1 LINE
SARAFFER ARCEDIT /HOME/GTI1WORK/SARAFFER/CAPP/JOHN_COHELP/EXPORT/UNSATZNNEW_F1
SARAFFER BUILD UNSATZNNEW_F1 LINE
SARAFFER ARCEDIT /HOME/GTI1WORK/SARAFFER/CAPP/JOHN_COHELP/EXPORT/UNSATZNNEW_F1
SARAFFER ARCEDIT /HOME/GTI1WORK/SARAFFER/CAPP/JOHN_COHELP/EXPORT/UNSATZNNEW_F1
SARAFFER BUILD UNSATZNNEW_F1 LINE
SARAFFER ARCEDIT /WORK/GTI1WORK/SARAFFER/CAPP/JOHN_COHELP/EXPORT/UNSATZNNEW_F1
JBSIEVER COPY ~SARAFFER/CAPP/JOHN_COHELP/EXPORT/UNSATZNNEW_F1 UNSATZN96
JBSIEVER ARCEDIT /HOME/GIS1WORK2/ROBSON/UNSATZN96
JBSIEVER ARCEDIT /HOME/GIS1WORK2/ROBSON/UNSATZN96
JBSIEVER ARCEDIT /HOME/GIS1WORK2/ROBSON/UNSATZN96
JBSIEVER ARCEDIT /HOME/GIS1WORK2/ROBSON/UNSATZN96
JBSIEVER ARCEDIT /WORK/GIS1WORK2/ROBSON/UNSATZN96
JBSIEVER ARCEDIT /HOME/GIS1WORK2/ROBSON/UNSATZN96
JBSIEVER ARCEDIT /HOME/GIS1WORK2/ROBSON/UNSATZN96
JBSIEVER ARCEDIT /WORK/GIS1WORK2/ROBSON/UNSATZN96
JBSIEVER ARCEDIT /HOME/GIS1WORK2/ROBSON/UNSATZN96
JBSIEVER ARCEDIT /HOME/GIS1WORK2/ROBSON/UNSATZN96
JBSIEVER ARCEDIT /WORK/GIS1WORK2/ROBSON/UNSATZN96
JBSIEVER ARCEDIT /HOME/GIS1WORK2/ROBSON/UNSATZN96
SJCHAR DOCUMENT UNSATZN96 DELETE SJCHAR
SJCHAR DOCUMENT UNSATZN96 CREATE SJCHAR
SJCHAR DOCUMENT UNSATZN96 DELETE SJCHAR
SJCHAR DOCUMENT UNSATZN96 UPDATE SJCHAR
SJCHAR DOCUMENT UNSATZN96 UPDATE SJCHAR
SJCHAR DOCUMENT UNSATZN96 UPDATE SJCHAR
SJCHAR DOCUMENT UNSATZN96 UPDATE SJCHAR
SJCHAR DOCUMENT UNSATZN96 UPDATE SJCHAR
SJCHAR RENAME UNSATZN96 DEPTHTOWATER
SJCHAR RENAME DEPTHTOWATER DEPTH2WT
SJCHAR DOCUMENT DEPTH2WT UPDATE SJCHAR
SJCHAR DOCUMENT DEPTH2WT UPDATE SJCHAR
SJCHAR COPY /WORK/GIS1WORK2/ROBSON/DEPTH2WT DEPTH2WT
SJCHAR DOCUMENT DEPTH2WT UPDATE SJCHAR
SJCHAR EXPORT COVER DEPTH2WT DEPTH2WT
SJCHAR BUILD DEPTH2WT LINE
SJCHAR EXPORT COVER DEPTH2WT DEPTH2WT
Arc attribute table
ARC/INFO
Internal number of from-node
Computed
Internal number of to-node
Computed
Internal number of poly to left of arc
Computed
Internal number of poly to right of arc
Computed
Length of arc in coverage units
Computed
Internal feature number
Computed
User-assigned feature number
User-defined
Depth to water, in feet
U.S. Geological Survey
Depth to water, in feet
U.S. Geological Survey
One-character-wide key used in plotting of text
U.S. Geological Survey
One-character-wide key to indicate lines which delineate depression features
U.S. Geological Survey
Arc attribute "CONTOUR" is the depth-to-water value in feet. Arc attribute "CNT_INT" is the integer equivalent of item "CONTOUR" for use in plotting depth-to-water values without three decimal places. Arc attribute "TEXTKEY" indicates how contour elevation values are drawn in a plotting routine: X = no text, no arc drawn. B = no text. L = text above line lc. P = text using point2 blank. G = text using point2 blank gray mask. Arc attribute "DEPRESSION" indicates whether or not a line delineates a depression feature. Lines that delineate depressions are coded as "Y"; non-depression features are coded as "N."
Not Available
Box 25046, MS 415, Denver Federal Center
Although this data set has been used by the U.S. Geological Survey, U.S. Department of the Interior, no warranty expressed or implied is made by the U.S. Geological Survey as to the accuracy of the data and related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the U.S. Geological Survey in the use of this data, software, or related materials. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
Depth to water contours geographic features
Depth to water contours geographic features
ArcIMS Image Map Service
A web-based interactive mapping system that accesses an ArcIMS Map Service running on certmapper.cr.usgs.gov.
Topological Vector Profile
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