 |
| THIS ISSUE |
| HOME |
| SUBSCRIBE |
Bathymetry: An In-depth StudyContributors: Peter August, URI Coastal Institute and URI Natural Resources Science; Michael Bradley, EDC; James Turenne, NRCS; Kathryn Ford, Massachusetts Office of Coastal Zone Management How deep is the water? How many times has a swimmer or boater asked this question? Whether you are canoeing on a salt pond or fishing in a quiet cove, knowing the bathymetry (the depth of the water) of Narragansett Bay and other coastal waters is essential information. Like all users of the state’s coastal waters, MapCoast scientists need accurate and up-to-date bathymetric data to help them get a picture of the seafloor. During the MapCoast User Conference in November 2004, detailed and accurate shallow-water (less than 5 meters) bathymetry data was one of the most requested data sets. Bathymetry data for MapCoast is primarily collected using fathometer soundings. In areas too shallow for a deeper water fathometer, researchers use highaccuracy GPS to collect measurements of depth by wading into shallow waters from shore. Using GIS technology, MapCoast scientists merge existing coastal elevation data with shallow- water bathymetry to create a seamless elevation model. Careful testing and statistical analyses are performed to ensure the resulting topographic and bathymetric data set is accurate. Using different GIS procedures, MapCoast scientists then create contour maps and other representations of elevation and depth used in resource management. While MapCoast bathymetric data sets are not intended for navigation, there are many scienti fic uses for these data. Bathymetry and the resulting contour lines give MapCoast researchers valuable information on the shallow-water landscape and allow them to define the boundaries of soil map units and underwater habitats. Detailed bathymetric data can be used for a variety of marine studies, including mapping eelgrass beds and identifying essential fish habitat. Bathymetry is also an important component for hydrographic modeling for examining current flow, and it is used for habitat restoration design (e.g., restoration of salt marshes) and analysis of sediment and contaminant transport. Detailed bathymetry has been developed for Ninigret and Quonochontaug ponds on the south shore of Rhode Island and for Greenwich Bay and Wickford Harbor. |
Rhode
Island Sea Grant |
Coastal Institute |