The plan is to use the EAARL system to map shallow (less than 1.5 secchi depth) and non-turbid areas in Estero Bay and nearshore areas. The SANDS system will be used in deeper areas and those which are turbid which includes the Caloosahatchee River.
The areas in and around the Caloosahatchee Estuary and Estero Bay Watershed have undergone dramatic increases in the rate of residential and commercial development as well as population growth during the past 15 years. As a result, a series of initiatives have been proposed to balance development and environmental interests in the region. Several recent initiatives including the development MFL and the Southwest Florida Feasibility Study (SWFFS) necessitate the development of hydrodynamic models of coastal waters in the Caloosahatchee Estuary and Estero Bay areas. One of the important data requirements for these models is the bathymetry. The information available at this time is dated (the last complete bathymetric survey is over 100 years old) and needs to be upgraded with a new survey. In addition, recommendations of the Estero Bay and Watershed Assessment completed in November of 1999 recommended the development of a Bay hydrodynamic and water quality model. Updated river, bay, and coastal bathymetry is required for these efforts.
The area for bathymetry collection and interpretation includes Estero Bay, Charlotte Harbor, Pine Island Sound, offshore regions of Sanibel and Captive Islands, and the Caloosahatchee, Loxahatchee and St. Lucie Rivers. In addition, a need for an Estero Bay and Charlotte Harbor estuarine mixing model has been identified by the Southwest Florida Regional Restoration Coordination Team and the Southwest Florida Feasibility Study. In order to create an accurate numerical model, current bathymetric data must be obtained. Bathymetry data is also needed for the creation of a seagrass vision maps (an NEP effort) and to populate the species response models being created as assessment tools for several restoration programs.
The USGS has developed a hydrographic survey system specifically designed to map in very shallow water. The system can acquire data in water depths of approximately 25cm, but in practice boat/motor draft limitations prevent surveying in water depths less than 45cm.
EAARL is a new airborne lidar that provides unprecedented capabilities to bays, the nearshore shoreface, benthic habitats, coastal vegetation, and sandy beaches. The EAARL sensor suite includes a raster-scanning-water penetrating full-waveform adaptive lidar, a down-looking color digital camera, a hyperspectral scanner, and an array of precision kinematic GPS receivers which provide for sub-meter geo-referencing of each laser and hyper-spectral sample. EAARL has the unique real-time capability to detect, capture, and automatically adapt to each laser return backscatter over a large signal dynamic range and keyed to considerable variations in vertical complexity of the surface target. EAARL limited to water depths greater than 50 cm and can penetrate the water column to approximately 1.5 secchi disk depth. The lidar has a ground footprint of 30cm with vertical and horizontal accuracies equal to the SANDS system. The swath width is 250m which converts to a spatial coverage of approximately 1 laser shot per square meter.
The project would use the EAARL system to map shallow (less than 1.5 secchi depth) and non-turbid areas in Estero Bay and nearshore areas. The SANDS system would be used in deeper areas and those which are turbid which include the Caloosahatchee River.
Work planned for FY 2003-2004 includes:
1. High resolution bathymetric surveying. 2. Post processing of the benchmark and hydrographic data.
3. Storage and maintenance all data and access to this data for reproduction as needed by the SFWMD.
4. A final data package to include the following:
Hard copy plot of locations of surveyed areas.
Digital ASCII XYZ data in UTM Zone17, GRS80/NAD83 horizontal coordinates, and NAVD88 vertical coordinates in tabular format. The SFWMD has also asked for the data to be projected into State Plane Coordinates, Florida East Zone (ft) NAD 83, and vertical datum National Geodetic Vertical Datum of 1929 (ft).
Copies of raw and processed digital data files on CD-ROM
U.S. Department of the Interior, U.S. Geological Survey, Center for
Coastal Geology
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