FLORIDA GEOGRAPHIC DATA LIBRARY DOCUMENTATION
VERSION 2005

TITLE: NATIONAL HYDROGRAPHY DATASET (NHD) - LANDMARKS, POINT

Geodataset Name:      NHDLMP
Geodataset Type:      SHAPE
Geodataset Feature:   POINT

GENERAL DESCRIPTION:

This dataset contains the spatial extent of landmarks for the 
National Hydrography Dataset (NHD) in the State of Florida.  The points 
represent features such as springs, wells, sinkholes, and gaging
stations.
DATA SOURCE(S):                   United States Geological Survey 
SCALE OF ORIGINAL SOURCE MAPS:    1:100,000
DATE OF AUTOMATION OR SOURCE:     1999
GEODATASET EXTENT:                State of Florida
FEATURE ATTRIBUTE TABLES:
Datafile Name: NHDLMP.DBF

ITEM NAME     WIDTH    TYPE   PRECISION

SHAPE           6    SHAPEPOINT   0
COM_ID         11    DECIMAL      0
FTYPE          24    CHARACTER    0
FCODE           5    CHARACTER    0
GNIS_ID         8    CHARACTER    0
NAME           99    CHARACTER    0
DESC          130    CHARACTER    0
DESCRIPT       24    CHARACTER    0

FEATURE ATTRIBUTE TABLES CODES AND VALUES:

ITEM           ITEM DESCRIPTION

SHAPE          Data attribute inherent to the ESRI shapefile format,
               which defines the data as a point, polyline, or polygon.

COM_ID         Unique common identifier of the NHD feature or reach

FTYPE          Features are classified by type. These feature types provide the
               basic description of the features. Each type has a name and
               a definition.
               GAGING STATION - A structure  used to measure the characteristics 
                                of a hydrographic feature. 
               SPRING/SEEP - A place where water issues from the ground naturally.
               RAPIDS - An area of swift current in a stream or river,
                        characterized by standing waves or by boulders and rocks.
               WELL - A pit or hole dug or bored into the earth for the extraction
                      of oil, water, other fluids, or gases.

FCODE          A five-digit feature code encodes the feature type and combinations
               of characteristics and values that can be assigned to a type. The
               first three digits encode the feature type, and the last two digits
               encode a set of characteristics and values. The general format of
               the feature code is FFFCC, in which FFF is the three-digit code for
               a feature type. CC is the two-digit code for a combination of values
               for characteristics associated with a feature type. If only the
               feature type is identified, these last two digits are assigned the 
               value "0".

GNIS_ID        GNIS identifier of the waterbody reach name. A "blank" means that
               the name is not populated. GNIS is an 8-digit code from the
               Geographic Names Information System developed by the USGS and the 
               USBGN. The Federally recognized name of each feature described in 
               the data base is identified, and references are made to a
               feature's location by State, county, and geographic coordinates.

NAME           Text of the reach name. A "blank" means that the name is not
               populated.

DESC           The description field uses a single character string to encode one
               or more characteristics and values for each feature code. The 
               general format of the character string is characteristic|value,  
               in which "characteristic" is the name of the characteristic. The
               vertical line character ("|") separates the characteristic and 
               value. "Value" is the value of the characteristic for the feature 
               code.

DESCRIPT       FGDL added item based on the item FTYPE

USER NOTES:

Please note that the NHD is designed to have many users nation wide
that use as well as update the dataset. By using the data set in shapefile
format it will no longer be possible to update the NHD. For information on 
how you can take part in the updating of NHD data, or how to get the latest
version, see their website: http://nhd.usgs.gov
The National Hydrography Dataset (NHD) is a feature-based database that
interconnects and uniquely identifies the stream segments or reaches that
comprise the nations surface water drainage system. It is based initially on
the content of the U.S. Geological Survey 1:100,000-scale Digital Line Graph
(DLG) hydrography data, integrated with reach-related information from the U.S.
Environmental Protection Agency Reach File Version 3.0 (RF3). More
specifically, it contains reach codes for networked features and isolated
lakes, flow direction, names, stream level, and centerline representations for
areal water bodies. Reaches are also defined to represent waterbodies and the
approximate shorelines of the Great Lakes, the Atlantic and Pacific Oceans, and
the Gulf of Mexico. The NHD also incorporates the National Spatial Data
Infrastructure framework criteria set out by the Federal Geographic Data
Committee.
The National Hydrography Dataset combines elements of the DLG and RF3: spatial
accuracy and comprehensiveness from the DLG and network relationships, names,
stream level, and a unique identifier (reach code) for surface water features
from RF3. The NHD supersedes DLG and RF3 by incorporating them, not by
replacing them. Users of DLG and RF3 will find the National Hydrography Dataset
both familiar and greatly expanded and refined. The NHD provides a national
framework for assigning reach addresses to water-related entities, such as
industrial dischargers, drinking water supplies, fish habitat areas, wild and
scenic rivers. Reach addresses establish the locations of these entities
relative to one another within the NHD surface water drainage network in a
manner similar to street addresses. Once linked to the NHD by their reach
addresses, the upstream/downstream relationships of these water-related
entities and any associated information about them can be analyzed using
software tools ranging from spreadsheets to geographic information systems
(GIS). GIS can also be used to combine NHD-based network analysis with other
data layers, such as soils, land use and population, to help better understand
and display their respective effects upon one another. Furthermore, because the
NHD provides a nationally consistent framework for addressing and analysis,
water-related information linked to reach addresses by one organization
(national, state, local) can be shared with other organizations and easily
integrated into many different types of applications to the benefit of all. The
National Hydrography Dataset is designed to provide comprehensive coverage of
hydrologic data for the U.S. While initially based on 1:100,000-scale data, the
NHD is designed to incorporate - and encourage the development of -
higher-resolution data required by many users. It will facilitate the improved
integration of water-related data in support of the application requirements of
a growing national user community and will enable shared maintenance and
enhancement.
For further research of NHD item definitions go to the "National Hydrology Dataset, 
Contents and Concepts" at:
http://nhd.usgs.gov/chapter1/index.html#_toc474479742
Certain scale datasets are not suitable for some project, analysis, or modelling 
purposes.  Please be sure you are using the best available data. 

1:24000 scale datasets are recommended for projects that are at the county
level.  1:24000 data should NOT be used for high accuracy base mapping such as
property parcel boundaries.

1:100000 scale datasets are recommended for projects that are at the
multi-county or regional level.

1:250000 scale datasets are recommended for projects that are at the regional or
state level or larger.

Vector datasets with no defined scale or accuracy should be considered suspect.
Make sure you are familiar with your data before using it for projects or
analyses.  Every effort has been made to supply the user with data
documentation.  For additional information, see the References section and the
Data Source Contact section of this documentation.  For more information
regarding scale and accuracy, see our web pages at:

http://www.geoplan.ufl.edu/education.html
These data are based on interpretation of available information and should
not be construed as legally binding.

FGDL QUALITY ASSURANCE STATUS:

-Converted coverage to shapefile using NHD ArcView Toolkit
-Reprojected data to FGDL Albers HPGN (See "Map Projection Parameters" below)
-Upcased all character records
-Changed original file name from "nhd" to "nhdlm"
-Joined shapefile with FCODE table
-Renamed DESCRIPT field to DESC
-DESCRIPT item was added based on the item FTYPE
-Clipped shapefile to State of Florida

REFERENCES:

The United States Geological Survey and 
The United States Environmental Protection Agency

DATA LINEAGE SUMMARY:

The NHD is produced by a joint effort between the Environmental Protection Agency 
(EPA) and U.S. Geological Survey (USGS). Data was downloaded by GeoPlan in coverage 
format from the USGS/NHD website (http://nhd.usgs.gov/) in June 2002. When received, 
data was in the following projection: Geographic, Datum: NAD 83, Spheroid: GRS80, 
units: Decimal Degrees. The shapefile was then clipped to the State of Florida, and 
projected to FGDL Albers HPGN.

MAP PROJECTION PARAMETERS:

Projection                           ALBERS
Units                                METERS
Datum                                HPGN
Spheroid                             GRS1980
1st standard parallel                24   0  0.000
2nd standard parallel                31  30  0.000
central meridian                    -84   0  0.000
latitude of projection's origin      24   0  0.000 
false easting (meters)               400000.00000
false northing (meters)              0.00000

DATA SOURCES CONTACT(S):

Name:      National Mapping Division, U.S. Department of Interior, U.S. Geological Survey 
Abbr.name: USGS		
Address:   12201 Sunrise Valley Drive 
           Reston, VA 20192   USA 							
Phone:     1-888-ASK-USGS (275-8747)			
Fax: 			
Web site: NHD - http://nhd.usgs.gov/index.html 
Mapping   Division - http://mapping.usgs.gov/index.html 	
Ftp site:		                 
Email:    nhd@usgs.gov 
              

FGDL CONTACT:

Name:                    Florida Geographic Data Library
Abbr. Name:              FGDL
Address:                 Florida Geographic Data Library
                         431 Architecture
                         PO Box 115706
                         Gainesville, FL  32611-5706
Web site:                http://www.fgdl.org
Contact FGDL:
      Technical Support:                http://www.fgdl.org/fgdlfeed.html
      FGDL Frequently Asked Questions:  http://www.fgdl.org/fgdlfaq.html
      FGDL Mailing Lists:               http://www.fgdl.org/fgdl-l.html
      For FGDL Software:                http://www.fgdl.org/software.html