In October of 2011, the EDEN project released a new version (Version 2, V2) of the EDEN Water Surface Model. This version replaces the last version (Version 1, V1) of the EDEN model . As part of this upgrade, most (4/1/00-6/30/11) EDEN water surfaces were recreated, new data was processed (1991-1999), and several new map datasets are now available (see below).
Spatially continuous interpolation of water surface across the greater Everglades is generated for daily median values of the water-level gages for the EDEN network beginning January 1, 1991. Surfaces are recorded as elevation in centimeters relative to North American Vertical Datum of 1988 (NAVD 88). More information on how water surfaces are created is available below.
The list of gages used to generate the daily water surface changes over time because gages are discontinued, new gages are constructed, or gages are added or removed from the EDEN network. The daily median output files provide users with the list of gages used for each day's water-level surface.
The EDEN surface-water model domain includes Water Conservation Areas 1, 2, and 3, Pennsuco Wetlands and the freshwater portions of Big Cypress National Preserve (BCNP) and Everglades National Park (ENP). Version 2 (V2) of the model added the northwest corner of ENP and southern portion of BCNP.
The EDEN domain is gridded into 400 x 400 meter cells that in total are referred to as the "EDEN grid" and which allow for analysis of subsets of the grid and GIS analysis of other data layers over the EDEN domain, such as ground elevation data, rainfall data, and water depth computation. Learn more about the EDEN Grid.
The EDEN project has created a series of new map datasets as part of this V2 release:
When used in conjunction with our modeled ground elevation map, derived data (such as depth, days since dry, etc.) can be calculated.
Most maps are available as NetCDF (.nc), GeoTiff (.tiff), and jpegs (.jpg).
The EDEN surface-water model (V2) will be fully documented in a USGS-series report planned for publication in Spring 2012. A summary of the revisions to the Version 1 (V1) model are listed below:
In order for EDEN users to more easily see what has changed between V1 and V2 of the model, a series of "Difference Maps" were created. EDEN difference maps show users how the daily water-level surfaces created with the V2 model differ from surfaces created with the V1 model. Some users may find that, for their study area, the newly revised surfaces are not significantly different from the previous surfaces. In this case, downloading all the new surfaces may not be necessary. Learn more and view EDEN Difference Maps.
EDEN daily surfaces are identified by the quality of the input water-level data used to create the surface. Input data is either real-time, provisional, or final:
The confidence index developed by Pearlstine and others (2007) for the V1 model was tested using the V2 model and measured water levels at benchmarks in the Everglades. For the V2 model, none of the parameters are strongly correlated with measured water levels therefore the parameters that define the areas of low confidence are not yet clear. However, over 82 percent of differences at benchmarks are plus or minus 5 centimeters which indicates the ability of the model to estimate the water levels extremely well in most areas of the Everglades.
The steps to create the daily water-level surfaces are summarized below:
The USGS retrieves water-level data daily from nearly 300 gaging stations. Most gages record and transmit several water-level values throughout the day, mostly hourly from recorders. A subset of these gages do not have telemetry and are manually read and added to the network when provisional and final data is produced. All transmitted data are entered and stored in the National Water Information System (NWIS), a database operated by the United States Geological Survey (USGS). There are over 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 (ENP), South Florida Water Management District (SFWMD), Big Cypress National Preserve (BCNP), and the USGS. The NWIS database transmits all recorded data to a local USGS FTP server where it is available for surfacing.
(Graphic from "Spatially Continuous Interpolation of Water Stage and Water Depths Using the Everglades Depth Estimation Network (EDEN), University of Florida, IFAS,CIR1521.)