Heather Henkel
200711
Everglades Depth Estimation Network (EDEN) Water Surfaces Data
digital files
http://sofia.usgs.gov/eden/models/watersurfacemod.php
Spatially continuous interpolation of water surface across the greater Everglades is generated for daily mean values of the water level gages for the EDEN network beginning January 1, 2000. Surfaces are recorded as elevations in centimeters relative to the North American Vertical Datum of 1988 (NAVD 88). These surfaces are served on the web as GIS data layers.
Spatially explicit hydrologic information can be critical in understanding and predicting changes in biotic communities in wetland ecosystems. Repeated field measurements, the traditional method of collecting water surface information, is labor intensive and doesn't produce spatially continuous data across large areas. For this reason the EDEN project was started to collect data from over 200 real time stage monitoring gages that automatically record and radio-transmit data. The project integrates existing and new telemetered water level gages into a single network. Combined with a high resolution ground elevation model it generates a daily continuous water surface and water depth for the freshwater greater Everglades.
20000101
20070930
ground condition
As needed
-81.3
-80.16
26.75
25
none
water level
hydrology
gages
water surface
stage
ISO 19115 Topic Category
environment
inlandWaters
elevation
006
007
012
Department of Commerce, 1995, Countries, Dependencies, Areas of Special Sovereignty, and Their Principal Administrative Divisions, Federal Information Processing Standard (FIPS) 10-4, Washington, DC, National Institute of Standards and Technology
United States
US
U.S. Department of Commerce, 1987, Codes for the identification of the States, the District of Columbia and the outlying areas of the United States, and associated areas (Federal Information Processing Standard 5-2): Washington, DC, NIST
Florida
FL
Department of Commerce, 1990, Counties and Equivalent Entities of the United States, Its Possessions, and Associated Areas, FIPS 6-3, Washington, DC, National Institute of Standards and Technology
Broward County
Collier County
Miami-Dade County
Monroe County
Palm Beach County
USGS Geographic Names Information System
Everglades National Park
Big Cypress National Preserve
Florida Bay
Gulf of Mexico
none
Greater Lake Okeechobee
Central Everglades
SW Big Cypress
Water Conservation Area 1
Water Conservation Area 2
Water Conservation Area 3
WCA1
WCA2
WCA3
none
none. The data from 10/1/2005 to 9/30/2007 are provisional.
Heather Henkel
U.S. Geological Survey
mailing and physical address
600 Fourth Street South
St. Petersburg
FL
33701
USA
727 803-8747 ext 3028
727 803-2030
sofia-metadata@usgs.gov
http://sofia.usgs.gov/eden/models/watersurfacemod.php
The graphic shows the area covered by the water surface data and the colors represent the differences in water surface elevation meters, The graphic is only representative of a single day, other maps will display differently.
JPEG
The Water Stage surfacing team includes Monica Palaseanu, Leonard Pearlstine, and Ikuko Fujisaki at the University of Florida, Ft Lauderdale Research and Education Center
Data are available as NetCDF files and as GeoTiff files. Daily Median Output Files are available as text files
Pearlstine, Leonard
Higer, Aaron;
palaseanu, Monica;
Fujisaki, Ikuko;
Mazzotti, Frank
2007
Spatially Continuous Interpolation of Water Stage and Water Depths Using the Everglades Depth Estimation Network (EDEN)
report
CIR
1521
Gainesville, Fl
Institute of Food and Agricultural Services, University of Florida
Full text of the document is available at: http://edis.ifas.ufl.edu/pdffiles/UW/UW27800.pdf
http://edis.ifas.ufl.edu/UW278
The Daily Median Output Files "median" files contain a list of the stations that were used to create water surfaces for that day. The "median_reject" files contain a list of gages that were not used during the creation of that day's water surface.
Data from all the gages were collected and evaluated for use in calculating the water surface for each day.
Horizontal positions are established by GPS observations and are referenced to the North American Datum of 1983 (NAD83). The desired horizontal accuracy is +/- 15 centimeters. This level of accuracy is consistent with GPS differential techniques which use two stations - a high-quality dual-frequency GPS receiver base station and a roving GPS station. The density and accuracy of a given GPS data observation varies from a few meters to a few centimeters according to the Position Dilution of Precision (PDOP) in the study area. Generally if the PDOP is observed to be excessive, data collection is discontinued or the data are discarded. The PDOP is an indicator of the positional accuracy of the GPS that be can derived from the current GPS satellite geometry, which varies continuously. Generally the smaller the PDOP number, the higher the data quality. The PDOP is a permanent part of the recorded data and is also included in the post processing procedures during reduction of the GPS observations to NAD 83. Where possible, the GPS base station has an ellipsoid height to an accuracy of two centimeters relative to the Continuously Operating Reference Stations (CORS) or the High Accuracy Reference Network (HARN), both operated by the National Geodetic Survey (NGS).
Source data (HAED) collected to better than +/- 15cm. Standard errors of cross-validation for the DEM range from ~7cm to 17cm depending on the EDEN subarea. This version is composed of new models created for WCA3N and the BCNP combined with the mosaic of two versions (i.e., eden_v002a for WCA1 and eden_v002c for all other EDEN subregions) that comprised EDEN_EM_JAN07. The previous mosaic was selected based on analysis of model performance in the water depth estimation process. The WCA1 surface was produced by removing all "upland" AHF points as defined by a reclassification of the Florida GAP process. For WCA1, the krigging model was developed based on statistics from the entire EDEN domain (the process for eden_v002a production). For each other EDEN sub-area (i.e., the other WCAs and the National Park) region specific krigging models were developed and applied.
The water surface model was created by the following steps:
1. Water-level data for all the EDEN gages are retrieved from an ftp server
2. Water-level data reported in NGVD 29 are converted to NAVD 88
3. Daily median water level is calculated
4. Linear interpolation is used to create boundary conditions along canals and levees
5. Radial Bias Function multiquadric interpolation of extended data (median water level from gages in marsh and interpolated values along canals) is used to generate continuous water level surfaces daily
6. The continuous water surface is predicted on the EDEN grid (400m x 400m)
7. Water depth is estimated by subtracting the EDEN ground digital elevation model (DEM) from the predicted water surface
The USGS retrieves water level data daily from 253 gaging stations including 225 telemetry-enhanced gages that record and transmit several water level values throughout the day, most hourly from recorders ranging from approximately 81 deg, 07 min 19 sec to 80 deg 13 min 05 sec West and from 25 deg 13 min 27 sec to 26 deg 40 min 47 sec North. An additional 28 gages do not have telemetry and are manually read and added to the network. All transmitted data are entered and stored in the National Water Information System (NWIS), a database operated by the USGS. There are a total of 240 gages used for water surface interpolation of the freshwater Everglades.
All gages in the EDEN network are operated and maintained by four separate agencies including Everglades National Park, South Florida Water Management District, Big Cypress National Preserve, and the USGS.
2007
Heather Henkel
U.S. Geological Survey
mailing and physical address
600 Fourth Street South
St. Petersburg
FL
33701
USA
727 803-8747 ext 3028
727 803-2030
sofia-metadata@usgs.gov
Surfacing Process:
The steps in preparing a daily surface from Everglades stage gaging stations are to collect the gaging station values as daily medians, create boundary conditions along canals/levees, generate the continuous surface using multiquadric radial basis function, and save the output into 400 meter output grids in netCDF and geoTIFF formats.
For each day that the surface is run, values for water stage are obtained from the USGS NWIS server for each gage listed in the EDEN master station list maintained by USGS, St Petersburg, Florida. Median daily values are calculated at each gage and stored in UTM, zone 17, NAD 1983 projection and datum, meter horizontal units. Vertical units are centimeters, NAVD 88. Where gage data is obtained in NGVD 29, it is converted to NAVD 88 using difference values for each gage. The difference values are provided in the EDEN master list.
Median stage values along specific canals are linearly interpolated every 200m between gages and extrapolated up to 3 kilometers beyond a gage when canals extend beyond the last gage. This interpolation/extrapolation will be used in the surfacing process to enforce boundaries at the canals between Everglades water conservation areas. The specific canals and the point locations interpolated/extrapolated in the canals are read from files maintained by USGS, St Petersburg, Florida.
Median stage for the day at each gage and each interpolated/extrapolated canal point location are combined as input for surface interpolation using the radial basis function routine in ArcGIS geostatistical analyst. The parameters are:
Kernel Functions: Multiquadric;
Parameter = 16.77
Neighbors to Include = 1
Include at least = 1
shape type = 8 sectors
angle = 350
major semiaxis = 31000
minor semiaxis = 30000
A boundary data layer is used to clip the surface interpolation to the EDEN area. The surface interpolation is saved to an ESRI GRID with 400m cell resolution aligned to the EDEN grid data layer. The prediction grid value at each cell is obtained from the interpolation surface by assigning to the grid cell the prediction value that corresponds to the center position of the grid cell. Both the boundary data layer and the EDEN GRID are maintained by USGS, St Petersburg, Florida.
Interpolation surface GRID files for each day are converted to geoTIFF and CF compliant netCDF files for achieving. The netCDF files collect 3 months of daily surfaces together in each file.
2007
Leonard Pearlstine
Everglades and Dry Tortugas Parks
mailing and physical address
South Florida Natural Resources Center
950 Krome Avenue
Homestead
FL
33030
USA
305 224-4228
305 224-4147
Leonard_Pearlstine@nps.gov
greater Everglades
Universal Transverse Mercator
17
0.9996
-81
0
500000
0
Coordinate Pair
400
400
meters
North American Datum of 1983
Geodetic Reference System 80
6378137
298.257
North American Vertical Datum of 1988
0.0001
centimeters
Explicit elevation coordinate included with horizontal coordinates
The CF-compliant metadata in the header of the NetCDF file provides spatial information for projecting the data into a GIS as well as the start date and time step for the time-series of data in the file. It also provides information about the conventions used for attributes in the dataset and the source software used to create the dataset.
The Daily Median Output text files provide the following information: the agency responsible for the data, the station id, X and Y location in UTM coordinates, median water values in cm, the year, month, and day of collection, Head or Tail gage, and area of data collection
NetCDF Climate and Forecast (CF) Metadata Conventions, Version 1.0, 28 October, 2003 at http://cf-pcmdi.llnl.gov/documents/cf-conventions/1.0/
Heather S.Henkel
U.S. Geological Survey
mailing address
600 Fourth St. South
St. Petersburg
FL
33701
USA
727 803-8747 ext 3028
727 803-2030
hhenkel@usgs.gov
Water Surfaces
No warrantees are implied or explicit for the data
netCDF
CF-1.0
.zip
Each file contains the daily data for 3 months
The files must be unzipped before use
16
http://sofia.usgs.gov/eden/models/watersurfacemod.php
The data may be downloaded from the SOFIA website
GeoTiff
unknown
.zip
Each file contains the daily data for 3 months
The files must be unzipped before use
55
http://sofia.usgs.gov/eden/models/watersurfacemod.php
The data may be downloaded from the SOFIA website
none
Heather S.Henkel
U.S. Geological Survey
mailing address
600 Fourth St. South
St. Petersburg
FL
33701
USA
727 803-8747 ext 3028
727 803-2030
hhenkel@usgs.gov
Water Surfaces Daily Median Output Files
No warrantees are implied or explicit for the data
ASCII
unknown
.zip
Each file contains 3 months (one-quarter year) of daily datasets
The files must be unzipped before use
0.5
http://sofia.usgs.gov/eden/models/watersurfacemod.php
The data may be downloaded from the SOFIA website
none
20080201
Heather Henkel
U.S. Geological Survey
mailing and physical address
600 Fourth Street South
St. Petersburg
FL
33701
USA
727 803-8747 ext 3028
727 803-2030
sofia-metadata@usgs.gov
Content Standard for Digital Geospatial Metadata
FGDC-STD-001-1998