Digital Elevation Model 5-meter

Abstract

The Digital Elevation Model 5-meter data set is a representation of land elevation in a raster data format. Elevation values are represented in feet.

This is a compliation of four different elevation data sets. Horizontal and vertical accuracy varies depending on the source of the data.

Purpose

Elevation data is needed for a wide variety of activities including construction, flood analysis, environmental analysis, agriculture and industrial activities.

Time Period of Content

  • Beginning date: 1950s
  • Ending date: 2007

Publish Date

1/2013

Originator

USGS, Northwest Florida Water Management District (NWFWMD), NOAA, Florida Fish and Wildlife Conservation Commission (FWC), South Florida Water Management District (SFWMD), Florida Geographic Data Library (FGDL)

Publisher

FDGL

Theme Keywords

elevation, topography, digital elevation model, lidar

Place Keywords

Florida

Source Scale

varies - 1:4,800 (estimated for LIDAR) to 1:24,000

Horizontal Accuracy

varies

Vertical Accuracy

varies: 9 inches for LIDAR up to 8 feet for 1:24,000 topo contour source

Process Steps

According to FGDL metadata:

The following source DEMs were used to create a statewide DEM. The sources are listed in order of priority:

1) Northwest Florida Water Management District (NWFWMD) DEM description: Received from NWFWMD district in 2012. This DEM was created from a variety of different sources, metadata from each source used by NWFWMD is included with the FGDL download and is located in the following folder: ...\meta\nwfwmd cell size: 2, 2 (meters) pixel type: floating point elevation units: feet elevation datum: NAVD88

2) NOAA FLIDAR Coastal DEM description: This DEM is based on coastal Lidar data sourced from the NOAA Coastal Services Center. Metadata from each source used by NOAA is included with the FGDL download and is located in the following folder: ...\meta\noaa cell size: 5.4329891, 5.4329891 (meters) pixel type: unsigned integer elevation units: inches elevation datum: NAVD88

3) Florida Fish and Wildlife Conservation Commission (FWC) Florida Statewide 5-Meter DEM description: this is a statewide DEM that has some gaps. The DEM was received from FWC in 2012. Note: the source vertical datum was NGVD29, which was converted to NAVD88. Original metadata for this source DEM is included with the FGDL download and is located in the following folder: ...\meta\fwc cell size: 5.4329891, 5.4329891 (meters) pixel type: floating point elevation units: meters elevation datum: NGVD29

4) Contour Derived DEM description: This DEM is based on 2ft contours from the coastal LiDAR project. The biggest portion of this source data is around Lake Okeechobee, where data was from Merrick. For more information on the contour data please see FGDL layers prefixed with "TOPO2FT_". cell size: 5.4329891, 5.4329891 (meters) pixel type: unsigned integer elevation units: inches elevation datum: NAVD88 (from FGDL)

According to Florida Fish and Wildlife Conservation Commission metadata:

The Florida Statewide 5-meter digital elevation model (DEM) was created to support an ongoing FWC project to precisely map and catalog aquatic habitat. The DEM was generated primarily from gridded Tagged Vector Contours (TVCs) produced by Florida Department of Environmental Protection. This data, representing over 1,000 USGS topographic maps from the 1950s to the 1980s, spans a variety of contour intervals including 1- and 2-meter and 5- and 10-foot. In addition to gridded TVCs, the FWC production process includes the introduction of over 90,000 surface control points to ensure vertical accuracy of the resulting 5-meter elevation model. The measured accuracy of the FWC-produced 5-meter DEM, using almost 10,000 independent test points, yields results that are within National Map Accuracy Standards for vertical accuracy. The National Map Accuracy Standard for vertical accuracy requires that the elevation of 90 percent of all points tested must be correct within 1/2 of the contour interval (USGS Fact Sheet FS-171-99, 1999). "The contour intervals vary across the [S]tate therefore the value for the accuracy also varies" (FWRI, 2009)

Format

ArcInfo GRID

Format Details

Projection

Florida Albers HARN

Field Names

Field Description Type
Value Elevation value in feet Float

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