Project Work Plan

A. GENERAL INFORMATION:

Project Title: High Resolution Bathymetric Mapping of South Florida Estuarine and Coastal Systems
Project Start Date: Aug. 2003 Project End Date: Sept. 2005
Project Funding: USGS Place-Based Studies Initiative
Principal Investigator: Mark Hansen
Email address: mhansen@usgs.gov
Phone: (727) 803-8747 ext 3036 Fax: (727) 803-2032
Mail address: 600 4th Street South, St. Petersburg, FL 33701

Project Summary:
High resolution, GPS based bathymetric surveying is a proven method to map river, lake, and ocean floor elevations. Several recent initiatives including the development Minimum Flows and Levels (MFL) and the Southwest Florida Feasibility Study (SWFFS) necessitate the development of hydrodynamic models of coastal waters in South Florida. One of the important data requirements for these models is the bathymetry. The information available at this time for most of South Florida is dated and needs to be upgraded with new surveys. This project supports several efforts including the Caloosahatchee, Loxahatchee, and St. Lucie MFL, the Southwest Florida Feasibility Study, and the S.W.I.M. designation of Charlotte Harbor.

Project Objectives and Strategy:
This project addresses the collection and interpretation of data necessary to develop the present day bathymetry of the lower portions of South Florida including: Estero Bay, Charlotte Harbor, Pine Island Sound, offshore regions of Sanibel and Captiva 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 strategy is to acquire bathymetric data for the aforementioned areas is to employ two methods which have been developed by the U. S. Geological Survey (USGS) and National Aeronautical and Space Administration (NASA). The USGS method is an acoustic based system named System for Accurate Nearshore Depth Surveys (SANDS), and the NASA method is an airborne LIDAR system named Experimental Advanced Airborne Research Lidar (EAARL).

Potential Impacts and Major Products:
The impacts of this effort directly address the need and requirements for developing Minimum Flows and Levels (MFL) in South Florida’s estuaries and rivers and for NEP species response models. All of these state-mandated efforts will utilize data from this project to develop hydrodynamic models. In addition, this project will provide information which is essential in understanding the ecological processes of South Florida’s coastal systems such as non-modeling efforts such as the determination of oligohaline zones in various rivers.

Collaborators: NASA Clients: South Florida Water Management District

B. WORK PLAN

Title of Task 1: High-Resolution Mapping of Estero Bay Estuary, Caloosahatchee River, and lower portions of Charlotte Harbor
Task Funding: USGS Place-Based Studies Initiative
Task Leaders: Mark Hansen
Phone: (727) 803-8747 ext 3036
FAX: (727) 803-2032
Task Status (proposed or active): Active
Task priority: High
Budget and Time Frame for Task 1: Aug. 2002 - Aug 2005
Task Personnel: Gina Peery

Task Summary and Objectives: High resolution, GPS based bathymetric surveying is a proven method to map river, lake, and ocean floor elevations. Of primary interest to the South Florida Water Management District (SFWMD) is the quantification of the present day bathymetry of Caloosahatchee Estuary and Estero Bay regions. This information will be used by water management decision-makers to develop Minimum Flows and Levels (MFL) and better preserve fragile habitats.

Work to be undertaken during the proposal year and a description of the methods and procedures: The plan to acquire bathymetric data for the aforementioned area is to employ two methods which have been developed by the U. S. Geological Survey (USGS) and National Aeronautical and Space Administration (NASA). The USGS method is an acoustic based system named System for Accurate Nearshore Depth Surveys (SANDS), and the NASA method is an airborne LIDAR system named Experimental Advanced Airborne Research Lidar (EAARL).

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 ~25cm, but in practice boat/motor draft limitations prevent surveying in water depths less than 45cm. Precise differential GPS receivers are used to measure boat position and dynamic elevation, a survey quality 200 kHz depth sounder acquires water depth measurements, and a motion sensor measures heave, pitch, and roll of the boat. A measurement is collected about every 3m along a survey line. The vertical accuracy of the system is +/- 8cm and +/- 4cm inches horizontally.

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 rasterscanning- 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 georeferencing 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 proposed work would use the EAARL system to map shallow (less than 1.5 secchi depth) and nonturbid 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.

Planned Outreach: Maps and reports will be available through the SOFIA web site.

C. BRIEF DESCRIPTION ON HOW PROJECT TASKS SUPPORT THE DOI AND USGS EVERGLADES RESTORATION SCIENCE PLANS

Restoring the Everglades involves returning essential functions to a large and diverse ecosystem that has had significant adverse impacts from man's activities over the past 50 years. This project provides scientific data to assure the quantity and quality of drinking water as well as agricultural and industrial water supplies, and in general improve the quality of life for all south Florida's inhabitants.

In keeping with the mission of the USGS to provide the Nation with reliable, impartial information to describe and understand the Earth, this project involves mapping and topographic studies that contribute to the safety, health, and well-being of Florida's citizens. The work conducted encompasses high quality data collection which will be utilized for hydrological and ecological modeling, and experimental research and monitoring.