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New study from SPCMSC compares wetland shoreline change analysis methods

SPCMSC Research Ecologist Kathryn Smith and team publish a new paper, “Coastal Wetland Shoreline Change Monitoring: A Comparison of Shorelines from High-Resolution WorldView Satellite Imagery, Aerial Imagery, and Field Surveys”

Photo showing complex geomorphology of the Grand Bay marsh landscape
Photo showing the complex geomorphology of the marsh landscape of the Grand Bay National Wildlife Refuge/Grand Bay National Estuarine Research Reserve in coastal Alabama and Mississippi. (Credit: Terrence McCloskey, USGS. Public domain.)

Wetlands are critically important resources to protect coastal communities from storms, provide habitat and refugia for economically important fish and shellfish species, act as water purifiers for floodwaters, and store carbon within organic rich sediments. Shoreline change analysis is an important environmental monitoring tool for evaluating coastal dynamics and vulnerability to hazards such as sea-level rise and storms, including for wetland environments. In many areas of the United States and the world, availability of modern high‐resolution wetland shorelines is non‐existent, or data are out‐of‐date due to data limitations or the labor‐intensive process for mapping these areas.

Traditionally, coastal wetland shorelines are mapped by manually digitizing the boundary between land and water using aerial imagery or by surveying the position on the ground using a GPS; both laborious and expensive methods. However, the availability of high-resolution satellite imagery and advances in remote sensing techniques now allow for the use of semi-automated methods for generating these data. The team evaluated the use of high-resolution WorldView (WV) satellite images to identify the position of salt marsh shorelines and compared the results to GPS field surveys and aerial imagery for estimating shoreline change rates within the Grand Bay National Estuarine Research Reserve in Mississippi. The results show that WV data were similar to field survey and aerial imagery data, but tended to overestimate erosion at high wave energy, unvegetated shorelines where sandy beaches and sand bars were seaward of the marsh. The authors conclude that high-resolution satellite imagery has several benefits like the ability to provide critical information for coastal wetland monitoring for large geographic areas, allowing rapid response to estimate the impacts of erosional events, and reducing the costs of labor-intensive practices such as field surveys.

For more information, see the article in Remote Sensing at https://doi.org/10.3390/rs13153030.

 

Read what else is new at the St. Petersburg Coastal and Marine Science Center.

 

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