Narragansett Bay Bathymetric Elevation Model at 30-Meter Resolution

Bathymetry for Narragansett Bay, Rhode Island was derived from fifteen hydrographic surveys containing 165,184 individual soundings. The data provides a Digital Elevation Model with 30-meter grid spacing, covering the estuary with thirteen 7.5-minute DEMs. Surveys used date from 1943 to 1957, with soundings ranging from 1.2 meters to -58.8 meters relative to mean low water.

Use Cases

• Model coastal processes and sediment transport using gridded elevation and water depth data across the estuary.
• Analyze seafloor topography changes by comparing elevation values from historical surveys (1943-1957).
• Generate shoreline boundary maps by identifying grid cells assigned null values (-32676) for land areas.
• Calculate average separation metrics between the 165,184 source soundings for survey density assessment.

Strengths

• Derived from 165,184 individual source soundings, providing a detailed foundation.
• Includes thirteen high-resolution 7.5-minute DEMs at 30-meter data spacing.
• Data cleaning documented, with four inconsistent points removed prior to processing.

Limitations

• Source survey data is historical, collected between 1943 and 1957, limiting contemporary accuracy.
• Land areas within the DEM are assigned a uniform null value (-32676), masking terrestrial topography.
• Some older, less accurate surveys were omitted, potentially creating data gaps in certain areas.

Provenance

Source

National Oceanic and Atmospheric Administration, Department of Commerce.

Collection Method

Derived from source hydrographic survey soundings; older, less accurate overlapping data was omitted before tinning.

Time Range

Source surveys dated from 1943 to 1957.

Freshness

Metadata was last updated in October 2024, though underlying source data is from 1943-1957.

Geography

Narragansett Bay, Rhode Island, United States.