The hydrography data sets were generated for the Front Range Infrastructure Resources (FRIR) Project as a base cartographic layer. The data set contains the project's 45 1:24,000-scale quadrangle demonstration area that covers the Front Range of Colorado, south from Ft. Collins to the southern portion of Denver metropolitan area (not including Highlands Ranch, Douglas County); and west from Denver International Airport to the eastern foothills of the Rocky Mountains. For more information on this project, visit the Colorado Front Range Infrastructure Resources Project web site: (URL:http://rockyweb.cr.usgs.gov/frontrange/datasets.htm) Procedures involved in compiling the hydrographic data include (1) obtaining 1 meter digital imagery and ancillary data for collecting, interpreting, and classifying the hydrographic features, (2) compiling the Digital Line Graph (DLG) vector data by 1:24,000-scale USGS quadrangle tiles, (3) merging the 1:24,000-scale quadrangle tiles into one seamless data set, and (4) translating and reattributing the features into user-friendly data sets. The translated attribution is described below in the Supplemental_Information section.
The demand for GIS data has increased recently, especially in rapidly growing metropolitan areas. Many state, regional, and local planning agencies require up-to-date hydrographic and other cartographic base information for various applications including modeling urban growth, determining land suitability for future development, monitoring land use changes and impacts on the environment, understanding land use patterns, and developing policies that could encourage or discourage certain land use zoning. Base cartographic layers are part of the USGS FRIR project cooperative effort to provide qualitative and quantitative information about infrastructure (aggregate, energy, water, habitat) features needed by growing urban regions like the Denver metropolitan area. The objective of the project is to develop GIS information about water and other themes in such a way that decision makers can use this information to make land use planning decisions, growth models and will be used by the project scientists for multiple studies of the changing landscape of the Front Range and the impact on various resources. In addition to hydrography, the USGS has created six other base cartographic layers consisting of: roads (FRIRD), miscellaneous transportation (FRIMT), railroads (FRIRR), manmade structures (FRIMS), public land survey system (FRIPL), and boundaries (FRIBD). There are two hydrography data sets, FRIHY contains line, polygon, and node attributed features and the FRIHYX contains point attributed features. The data layers are available at http://rockyweb.cr.usgs.gov/frontrange/datasets.htm
CODES: HYDROGRAPHY OVERLAY This document lists the codes specific to the hydrography coverage as they pertain to item fields. The original classification system is taken from DLG major/minor attribute codes. The CAT item specifies the overlay type and takes the place of DLG major codes. See http://rockyweb.cr.usgs.gov/nmpstds/dlgstds.html for the complete document of DLG attributes. Field Definitions: CAT Theme Overlay PIC Primary Identification Code DSC Descriptive Code UNT Elevation Units (feet or meters) ELV Elevation LABEL Feature Definition MATT Redefined PIC and DSC Codes into one field SAMPLE .AAT INFO FILE CAT = 5 hydrography overlay PIC = 412 stream DSC = 610 intermittent UNT = 0 no value ELV = 0.0 no value LABEL = Intermittent Stream Feature Definition ** REDEFINED ITEMS ** MATT =414610 combination of PIC and DSC codes -------------------- !! ATTENTION !! NEATLINE: designated by PIC and DSC codes of 777 Null values: '9's are used to fill in blank fields -------------------- ** PIC codes for LINE features: PIC Definition 200 shoreline 201 manmade shoreline 202 closure line 605 right bank 606 left bank Note: - Swamp/Marsh-inundation area extents do not have line codes and carry null values. ** PIC codes for POLYGON features: PIC Definition 101 reservoir 102 covered reservoir 105 inundation area 106 fish hatchery or farm 107 industrial water impoundment 109 sewage disposal pond or filtration plant 111 marsh, wetland, swamp or bog 124 filtration pond ** PIC codes for POINT features: (see FRIHYX) PIC Definition 300 spring 301 non-flowing well 302 flowing well 303 riser 305 windmill ** PIC codes for NODE features: PIC Definition 300 spring 302 flowing well 501 upper origin of stream 502 upper origin of stream at water body 504 stream entering water body 505 stream exiting water body ** PIC codes for MULTIPLE ELEMENT: attributes that can be applied to NODES, LINES, POLYGONS, or POINTS: PIC Definition PIC Definition 403 gaging station 415 aqueduct 404 pumping station 416 flume 405 water intake 417 penstock 406 dam or weir 418 siphon 408 spillway 420 wash or ephemeral drain 412 stream 421 lake or pond 414 ditch or canal ** DSC codes: descriptive code of PIC codes. DSC Definition DSC Definition 601 underground 610 intermittent 602 overpassing 612 submerged or sunken 603 elevated 614 dry 604 aqueduct/tunnel 617 underpassing 618 earthen construction 708 underpassing, intermittent stream ** UNT codes: UNT Definition 1 feet 2 meters ** ELV codes ELV Definition Is the water surface elevation for a body of water as it appears on the USGS 1:24,000-scale printed map.
The imagery used in interpretation of hydrographic features was 1997 digital orthorectified imagery.
This data was collected from 1-meter resolution orthorectified scanned imagery (1997). The IFSAR imagery was used for horizontal accuracy. The data is revised from the original DLG vector data that was collected at 1:24000-scale within the 40 foot map accuracy standards. See DLG standards at (http://rockyweb.cr.usgs.gov/nmpstds/dlgstds.html) The data was collected for government use and represents the results of data collection for a specific activity. USGS makes no representation as to the suitability or accuracy of the data for any other purpose and disclaims any liability for errors that the data may contain. As such, it is only valid for its intended use, content, time, and accuracy specifications. While there are no explicit constraints on the use of the data, please exercise appropriate and professional judgment in the use and interpretation of this data. Acknowledgment of the U.S. Geological Survey would be appreciated for products derived from this data.
U.S. Geological Survey, Rocky Mountain Mapping Center, Denver Federal Center Bldg 810, P.O. Box 25046, MS 516
The final editing and structuring of these data sets were completed by the FRIR project members at the Rocky Mountain Mapping Center.
The attribution for the hydrography data was verified for consistency throughout the demo project area. Check plots were used to compare attribution and spatial extent with the photography. See Part 3, Attribute Coding of Standards for Digital Line Graphs at http://rockyweb.cr.usgs.gov/nmpstds/dlgstds.html See Entity_and_Attribute_Information and Supplemental_Information_Identification.
Polygon and chain-node topology present. All areas are closed polygons containing one label point. All arcs have an attribute code, nodes will have an attribute code if appropriate. The data set will have an unattributed polygon if not a hydrographic feature.
Hydrographic feature density consists of flowing water, standing water, manmade hydrographic structures, and wetlands. The region is considered a representative pattern (feature density) with capture conditions according to USGS 1:24000 mapping standards. Use of this data at larger scales may be incomplete. Reservoirs and pond/lake attributes are used interchangeably in some areas, with pond/lake being the most frequent and reservoirs representing man-made water bodies. This can be attributed to the map interpreter collecting the data. Both streams and ditches appear as single and double-lined. Polygons smaller than 50 ft. were collected as point features in Coverage FRIHYX. Point features e.g.-wells, springs, windmills, pump stations, gaging stations, and polygons smaller than 50 ft. are collected in the FRIHYX coverage. See capture conditions in Part 2- Hydrography, Standards for Digital Line Graphs at http://rockyweb.cr.usgs.gov/nmpstds/dlgstds.html
The hydrographic vector data is within 40 ft. to the ground planimetry. The original data is from a mosaic of photorevised 1:24000-scale DLGs derived from stable-base 1:24000-scale USGS topographic maps. Digital orthorectified imagery at a 1-meter resolution was used to collect features. Magnitude imagery from IFSAR (Interferometric Synthetic Aperture RADAR), with a horizontal accuracy of 2.5 meters and vertical accuracy of 2.0 meters, was used to verify horizontal placement of the features. The IFSAR imagery was collected by Intermap Technologies. See National Map Accuracy Standards at http://mapping.usgs.gov/standards/
Imagery was used to manually interpret and classify the hydrographic features.
Interpretation/Compilation - Features were visually identified, interpreted, and classified according to the USGS DLG Limited Update Standards except that data was collected so that 90 per cent of the well-defined features are within 40 ft. to the ground planimetry. The data is interpreted and compiled in blocks of 1:24,000-scale quadrangles. Once completed the data is edge-matched and paneled together into the seamless demonstration area. Final review of the data was to verify attribution, add additional attribution, and move features to geographically match the imagery.
FRIHY items are used to describe the physical and cultural characteristics of node, line, and polygon elements. Attribute codes are used to reduce redundant information, provide enough reference information to support integration with larger data bases, and describe the relationships between cartographic elements. See Supplemental_Information for item definitions. FRIHY.PAT: COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC ALTERNATE NAME 1 AREA 8 18 F 5 9 PERIMETER 8 18 F 5 17 FRIHY# 4 5 B - 21 FRIHY-ID 4 5 B - 25 CAT 2 2 I - 27 PIC 3 3 I - 30 DSC 3 3 I - 33 UNT 1 1 I - 34 ELV 7 7 N 1 41 LABEL 50 50 C - ** REDEFINED ITEMS ** 27 MATT 6 6 I - FRIRHY.AAT: COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC ALTERNATE NAME 1 FNODE# 4 5 B - 5 TNODE# 4 5 B - 9 LPOLY# 4 5 B - 13 RPOLY# 4 5 B - 17 LENGTH 8 18 F 5 25 FRIHY# 4 5 B - 29 FRIHY-ID 4 5 B - 33 CAT 2 2 I - 35 PIC 3 3 I - 38 DSC 3 3 I - 41 UNT 1 1 I - 42 ELV 7 7 N 1 49 LABEL 50 50 C - ** REDEFINED ITEMS ** 35 MATT 6 6 I - FRIHY.NAT COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC ALTERNATE NAME INDEXED 1 ARC# 4 5 B - 5 FRIHY# 4 5 B - 9 FRIHY-ID 4 5 B - 13 CAT 2 2 I - 15 PIC 3 3 I - 18 DSC 3 3 B - 21 LABEL 50 50 C - ** REDEFINED ITEMS ** 15 MATT 6 6 I - FRIHYX items are used to describe the physical and cultural characteristics of point elements. Attribute codes are used to reduce redundant information, provide enough reference information to support integration with larger data bases, and describe the relationships between cartographic elements. See Supplemental_Information for item definitions. FRIHYX.PAT: COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC ALTERNATE NAME 1 AREA 8 18 F 5 9 PERIMETER 8 18 F 5 17 FRIHYX# 4 5 B - 21 FRIHYX-ID 4 5 B - 25 CAT 2 2 I - 27 PIC 3 3 I - 30 DSC 3 3 I - 33 LABEL 50 50 C - ** REDEFINED ITEMS ** 27 MATT 6 6 I -
CAT Theme Category (DLG Hydrography = 050) PIC Primary Identification Code DSC Descriptive Code UNT Units ELV Elevation LABEL Feature Definition MATT Redefined PIC and DSC Codes into one field
Rocky Mountain Mapping Center, Denver Federal Center Bldg. 810 Box 25046, MS 516
Contact via email (FAX 303-202-4354)
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. 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.
Front Range infrastructure resources hydrography geographic features
Front Range infrastructure resources hydrography geographic features
ArcIMS Image Map Service
A web-based interactive mapping system that accesses an ArcIMS Map Service running on certmapper.cr.usgs.gov.
Rocky Mountain Mapping Center Denver Federal Center Bldg 810 P.O. Box 25056, MS 516