| Hydrography USGS 1:24,000 DLG-SDTS (line) | |
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Data format: SDE Feature Class File or table name: GISLIB.HYDRO_024K_SDTS_LINE Coordinate system: Transverse Mercator Theme keywords: inlandWaters, River, Lake, Streams, Canals, Hydrography, Water, Wetlands, DLG Digital Line Graph |
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Abstract:
This dataset is the U.S. Geological Survey's 1:24,000 Digital Line Graph (DLG) representing water and wetland features from USGS 7.5 minute quad map. The Digital Line Graphs (DLG's) are the U.S. Geological Survey, National Mapping Division, Vector Program's response to the nation's need for accurate and consistent geospatial digital data in vector format. Updates to the dataset were made using 1995 DOQQ's on a number of the individual quads (refer to enclosure quadlist.doc) that comprise this dataset. |
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Metadata elements shown with blue text are defined in the Federal Geographic Data Committee's (FGDC) Content Standard for Digital Geospatial Metadata (CSDGM). Elements shown with green text are defined in the ESRI Profile of the CSDGM. Elements shown with a green asterisk (*) will be automatically updated by ArcCatalog. ArcCatalog adds hints indicating which FGDC elements are mandatory; these are shown with gray text.
This dataset is the U.S. Geological Survey's 1:24,000 Digital Line Graph (DLG) representing water and wetland features from USGS 7.5 minute quad map. The Digital Line Graphs (DLG's) are the U.S. Geological Survey, National Mapping Division, Vector Program's response to the nation's need for accurate and consistent geospatial digital data in vector format. Updates to the dataset were made using 1995 DOQQ's on a number of the individual quads (refer to enclosure quadlist.doc) that comprise this dataset.
This dataset is suitable for cartographic applications and may be used for identification of hydrological features.
The U.S. Geological Survey (USGS) has made available Digital Line Graph level 3 (DLG-3) data in the Spatial Data Transfer Standard (SDTS) format since1993. The Spatial Data Transfer Standard (SDTS) offers a method for standardizing the transfer of spatial data and has been adapted as the format for transfer of all vector data from the National Digital Cartographic Data Base. The dataset was accepted in the SDTS format as received from USGS. There has not been any QA performed on the dataset other than to repair labelerrors. The quads as provided from the USGS have not been edgematched. The field 'edge' was added to the attributes in order to code quad boundary arcs as -99 to facilate cartographic applications. Refer to Entity Attributes for a full description of attribute coding and Data Quality Process Step on what process was performed. The listing for the quads used to create this dataset and the map date for each quad is found in quadlist.doc file under enclosures. There have been coding problems found in this dataset and users should be aware that they may exist in the users area of interest. If a coding error is found notify DIAS staff so we may add the quad and problem to the list below. Corrections to these errors are not scheduled at this time Quad 5516 some stream arcs are coded 0500421 (lake or pond)
publication date
The St. Johns River Water Management District prepares and uses information for its own purposes and this information may not be suitable for other purposes. This information is provided "as is". Further documentation of this data can be obtained by contacting: St. Johns River Water Management District, Division of Integrated Application Systems, Post Office Box 1429, Palatka, Florida, 32178-1429, (386) 329-4500.
P.O Box 1429
Refer to Positional_Accuracy element
Topological requirements include: lines must begin and end at node points, lines must connect to each other at nodes, lines do not extend through nodes, left and right areas are defined for each line element and are consistent throughout the file, and the lines representing the limits of the file (neatline) are free of gaps. The tests of logical consistency were performed by the USGS PROSYS program. The Neatline was generated by connecting the four corners of the digital file, as established during initialization of the digital file. All data outside the enclosed region were ignored and all data crossing these geographically straight lines were clipped at the neatline. Data within a specified tolerance of the neatline were snapped to the neatline. Neatline straightening aligned the digitized edges of the digital data with the generated neatline, that is, with the longitud/latitude lines in geographic coordinates. All internal areas were tested for closure using PROSYS. (source USGS)
For Digital Revision Status = Not Revised: Data completeness reflects the content of the source quadrangle. Features may have been eliminated or generalized on the source graphic, due to scale and legibility constraints. For Digital Revision Status = Limited Update: This file has undergone limited update digital revision. The file contains only: those features that are photoidentifiable on monoscopic source, supplemented with limited ancillary source, and those features, present on the original source quadrangle, that can not be reliably photoidentified but that are not considered particularly prone to change. For Digital Revision Status = Standard Update: This file has undergone standard update digital revision. The data completeness of this file meets NMD Standards for feature content. (source USGS)
For Digital Revision Status = Not Revised
For Hypsography, Hydrography, and Survey Control and Markers Only: For digital Revision Status = Not revised:
spatial and attribute information
SJRWMD staff downloaded the SDTS hydrological datasets from the USGS via ftp site by individual quads identified within the District. On completion of the download, the quads were converted into coverages using the sdts2cov.aml provided by the USGS. Topology was checked and any corrections required were made to the quads. In order to join all the quads into SDE certain items required removal using the DROPITEMS command in ARC/INFO. The number of items that were dropped varied by quad only those items consistent with all quads were retained. The coverages were randomly checked for edgematching and found to have significant variation that would require extensive processing. It was determined that the coverages would not be joined into a single contiguous layer, but added to SDE as individual quads. Detailed methodology and amls used can be found under enclosures. The quads were projected into UTM zone 17 NAD83/HARN. It should be noted that three quads 3514,3414 and 3310 were found to have the datum NAD27 rather than NAD83. Any future quads to be added to this dataset should be check to verify that that the quad is in the correct datum before projecting into the HPGN datum.
This Digital Line Graph was digitized from the USGS source quadrangle, by either the National Mapping Division, one of their cooperators or one of their contractors. The digital data were produced by one of the following methods, which all resulted in a scanning/digital resolution of at least 0.001 inches. Stable base scanning process: the resulting raster data were vectorized and then attributed on an interactive editing station: paper map scanning process: the resulting raster data were vectorized and then attributed on an interactive editing station. The stable base resulting raster data were then manually digitized and attributed on an interactive editing station. The paper map resulting raster data were then manually digitized and attributed on an interactive editing station. Manually digitizing from either a stable-based copy of the graphic material or a paper map using a digitizing table to capture the digital data; attribution was performed either as the data were digitized or on an interactive editing station after the digitizing was completed. The determination of the DLG production method was based on vaious criteria, including feature density, featuer symbology, and availability of production systems. Four control points corresponding to the four corners of the quadrangle were used for registration during data collection. An eight parameter projective transformation was performed on the coordinates used in the data collection and editing systems to register the digital data to the internal coordinates. The DLG data were checked for position and/or classification by one or more of the following processes: - comparing plots of the digital data to the graphic source or to the digital raster scan. For Digital Revision Status = Limited Update: This file has undergone limited update digital revision. Limited update revision uses monoscopic imagery and limited ancillary source with no field verification
Metadata imported.
Internal feature number.
ESRI
DLG-3 hydrography attribute code; see Overview description for complete list
Indicates if there has been a photorevision
A Feature's relation to ground may be 'U' underground, 'E' elevated, 'T' tunnel, or ' ' not applied
A feature's vertical relation may be 'O' overpassing, 'U' underpassing or ' ' not applied
Indicates Right or Left bank
Status of man-made structure 'U' underconstruction, 'A' abandon
Salt present 'Y' (applied) or blank
'Y' applied or blank
'Y' (applied) or blank
'Y' (applied) or blank
'Y' (applied) or blank
'Y' (applied) or blank
'Y' (applied) or blank
'Y' (applied) or blank
'Y' (applied) or blank
elevation to the nearest 0.01 meter: -9999.99 indicates not applied
Integers to the nearest degree: -99 indicates not applied
River miles to the nearest 0.1 mile: -999.9 indicates not applied
'Y' (applied) or blank
The specified mixture or combination of one or more elements.
'Y' (applied) or blank
'Y' (applied) or blank
coded field used to distinguish quad boundaries (-99) from other line features
SJRWMD
default - not a quad boundary
Quad boundary
Feature geometry.
ESRI
DLG3 Attibute codes are used to describe the physical and cultural characteristics of DLG node, line, and area elements. Attribute codes are used to reduce redundant information, provide enough reference information to support integration with larger data base, and describe the relationships between cartographic elements. Each DLG element has one or more attribute codes composed of a three digit major code and a four digit minor code. For example, with the 1:24000-scale DLG data, the line attribute code 050 0412 has a major code (050), meaning hydrography, with a minor code (0412) meaning stream.
U.S. Department of the Interior, U.S. Geological Survey, 1987 Digital Line Graphs from 1:24000-Scale Maps--Data Users Guide 1; Reston, Virginia Softcopies in ASCII, Wordperfect, and PostScript Format available at:
ftp://mapping.usgs.gov/pub/ti/DLG/. U.S. Department of the Interior, U.S. Geological Survey, 1990, Standards for Digital Line Graphs, Reston, VA, 1994.
The following are the entities in the Hydrography theme which are identified by the ENTITY_LABEL attribute:
ENTITY_LABEL
(DLG-3 code) Definition
0500001 Upper origin of stream
0500002 Upper origin of stream at water body
0500003 Sink, channel no longer evident
0500004 Stream entering water body
0500005 Stream exiting water body
0500100 Alkali flat
0500101 Reservoir
0500102 Covered reservoir
0500103 Glacier or permanent snow field
0500104 Salt evaporator
0500105 Inundation area
0500106 Fish hatchery or farm
0500107 Industrial water impoundment
0500108 Area to be submerged
0500109 Sewage disposal pond or settling basin
0500110 Tailings pond or settling basin
0500111 Marsh, wetland, swamp, or bog
0500112 Mangrove area
0500113 Rice field
0500114 Cranberry bog
0500115 Flats (tidal, mud, sand, or gravel)
0500116 Bays, estuaries, gulfs, oceans, or seas
0500117 Shoal
0500118 Soda evaporator
0500119 Duck evaporator
0500121 Obstruction area in water area
0500200 Shoreline
0500201 Manmade shoreline
0500202 Closure line
0500203 Indefinite shoreline
0500204 Apparent limit
0500205 Outline of a Carolina bay
0500206 Danger curve
0500207 Apparent shoreline
0500208 Sounding datum
0500209 Low-water line
0500299 Processing line
0500300 Spring
0500301 Non-flowing well
0500302 Flowing well
0500303 Riser
0500304 Geyser
0500305 Windmill
0500306 Cistern
0500400 Rapids
0500401 Falls
0500402 Gravel pit or quarry filled with water
0500403 Gaging station
0500404 Pumping station
0500405 Water intake
0500406 Dam or weir
0500407 Canal lock or sluice gate
0500408 Spillway
0500409 Gate (flood, tidal, head, or check)
0500410 Rock
0500411 Crevasse
0500412 Stream
0500413 Braided stream
0500414 Ditch or canal
0500415 Aqueduct
0500416 Flume
0500417 Penstock
0500418 Siphon
0500419 Channel in water area
0500420 Wash or ephemeral drain
0500421 Lake or pond
0500422 Coral reef
0500423 Sand in open water
0500424 Spoil area, dredge area, or dump area
0500425 Fish ladders
0500426 Holiday area
7 spaces No DLG-3 entity but has other attributes
Post Office Box 1429
The St. Johns River Water Management District prepares and uses information for its own purposes and this information may not be suitable for other purposes. This information is provided "as is". Further documentation of this data can be obtained by contacting: St. Johns River Water Management District, Division of Integrated Application Systems, Post Office Box 1429, Palatka, Florida, 32178-1429, (386) 329-4500.
ARC/INFO Export Format - UNIX Compression
There is no charge for downloading data from the DISTRICT web site at http://www.sjrwmd.com. Data can be orded on CD-ROM as instructed on the web site.
1. Use the DISTRICT website: http://www.sjrwmd.com to download data, or 2. Call or email to organizations listed under Distributor. Spatial data are in ARC/INFO interchange formats.
Post Office Box 1429