Explanation of Terms and Methods: Water-Level Data - Everglades Depth Estimation Network (EDEN)

Everglades Depth Estimation Network (EDEN) for Support of Biological and Ecological Assessments

Explanations of Terms and Methods (for Water-Level Values)

Operating Agency
EDEN Station Name
USGS NWIS Agency Code and ID
Location Area
Data Links
Datum Information
Ground Elevation and Vegetation Information
Vegetation Community
Type of Station

Operating Agency:
BCNP	Big Cypress National Preserve
ENP	Everglades National Park
SFWMD	South Florida Water Mangement District
USGS	U.S. Geological Survey

EDEN Station Name:

The station name used in the site is specific to the EDEN site. It generally is the same name as the agency station name, but there could be slight variations (either this is a shortened form, or a modified form). For example:

EDEN name: 3A9; Station name used by operating agency: 3A9+
EDEN name: 3AN1W1; Station name used by operating agency: 3AN1W1+

USGS NWIS Agency Code and ID:
USGS NWIS Agency Code:
Portion of primary key in USGS NWIS database used to define what agency collected data at a gage. Values: FL005 = South Florida Water Management District USNPS = U.S. National Park Service (includes Everglades National Park and Big Cypress National Preserve) USGS = U.S. Geological Survey
USGS NWIS ID:
Numeric portion of primary key in NWIS database used to uniquely define gage record (usually 8 digits or 15 digits in length). Example: 261116080442500

Location Area:
Area of Everglades where gage is located (gages along canals are reported by the canal name, gages across canals are reported by what area the headwater or tailwater gage measures)
Marsh Stations Choices:	Canal Stations Choices:	Coastal Stations Choices:
BCNP	Hillsboro Canal	Coast of Florida Bay
ENP	Tamiami Canal	Coast of Gulf of Mexico
WCA1	L-40
WCA2A	etc.
WCA2B
WCA3A
WCA3B
Pennsuco Wetlands

Data Links:
Links are provided to the following data (when available):
Daily Water Level Percentiles	Link to daily water level percentiles used to monitor water levels during the ERTP period and to compare water levels during the ERTP period with the water levels that occurred during the IOP.
Recent Hourly Data	Link to most recent 31 days of hourly data on the NWISweb website
Recent Daily Data	Link to daily values of water level for period of record available on NWISweb website
Salinity Data	Link to salinity values for period of record available on NWISweb website
Historic Hourly Data	Link to hourly dataset (text file) for period 10/1/1999 to 9/30/2005 on SOFIA Website
Evapotranspiration Data	Link to evapotranspiration data at the gage location
Rainfall Data	Link to rainfall data based on NEXRAD data at the gage location
NWIS Station location map	Link to station map on the NWISweb website
(For help on navigating the NWIS Data site, see the NWIS help pages.)
Other Database Links	Link to other agency databases with data for gage prior to 10/1/99 or for more recent data not available on EDEN site

Datum Information:
Why are all gage data not referenced to the same datum?	Prior to 1991, all water gages were surveyed to the National Geodetic Vertical Datum of 1929 (NGVD29) in Florida, a vertical reference from which Elevations can be measured to provide relative differences between water levels at gages. In 1991, the North American Vertical Datum of 1988 (NAVD88) was established and some gages were referenced from this new vertical reference. In south Florida, the difference between elevations referenced in NGVD29 and elevations referenced to NAVD88 are between 1 and 2 feet depending on the location. (See wwwest.ngs.noaa.gov/faq.shtml for more information about vertical datums.) Data for many gages in the EDEN network are referenced to NGVD29 by the operating agencies. When posted to EDENweb, they have been converted to NAVD88 using the conversion value documented on the station information page. Some gages operated by the USGS have not yet been converted to NAVD88. Users are advised to note the datum of all datasets to avoid using or comparing data with different datums.
How do I convert data at a gage from one datum to another?	The Station Information page for each gage on EDENweb provides the value to convert data at the gage from NGVD29 to NAVD88: For data in NGVD29, ADD the conversion value For data in NAVD88, SUBTRACT the conversion value For example: Site 69: On 01/16/07 at 12:00, gage height = 8.63 ft. NGVD29 To convert to NAVD88: 8.63 + (-1.66) = 6.97 ft. NAVD88 For example: Site L28_GAP: On 01/21/07 at 01:00, gage height = 10.22 ft. NAVD88 To convert to NGVD29: 10.22 - (-1.42) = 11.64 ft. NAVD88
How were the vertical conversions at gages determined by EDEN?	The operating agencies provided the vertical conversions at most gages. For gages only surveyed to NAVD88, the datum conversion was estimated using the CORPSCON 6.0 for VERTCON version 2.5 grid modified by the USACE Jacksonville District to incorporate the CERP vertical control network established in 2001-2002 (Rory Sutton, USACE). More information about CORPSCON 6.0: http://crunch.tec.army.mil/software/corpscon/corpscon.html

Ground Elevation and Vegetation Information:

Only the most current measurement of ground elevation and observation of vegetation are provided. When new data are collected, previous data are replaced.

Ground elevation at gages is determined in one of two ways:

Ground elevation was provided by the operating agency if one measurement of ground elevation is indicated. Generally, no data of measurement is available.
Water depth was measured or ground elevation was surveyed at a minimum of 6 locations in the major vegetation community surrounding the water level gaging station. For water depth measurements, the ground elevation at each site was calculated by subtracting the water depth from the water level reading at the gage. The ground elevations for all measurements were averaged to compute the reported value.

Protocol for 6-location method for collection of data at a water level (stage) gage is available.

Vegetation Community:

Vegetation community at the gage, field descriptions are categorized into major communities for freshwater and tidal gages.

Choices for freshwater gages:

Slough or open water
Wet prairie
Ridge or sawgrass and emergent marsh
Exotics and cattail
Upland
Canal (gage constructed in a canal along a levee or in the marsh but not at a canal structure)
Other (mostly wetland shrub and wetland forested)

Choices for tidal gages:

Marsh
Upland
Forest
Open water (river, canal, bay, etc.)

Type of Station:

Physical Location: Canal and marsh indicate stations located in uncontrolled regions, canal structure indicates a station located within a canal at a structure, usually with an associated station on the other side of the structure, marsh structure indicates a station located in the marsh at a structure, usually with an associated station on the other side of the structure. In both cases, the associated station does not have to be of the same type (canal or marsh). Values: