Previous studies of shorelines have relied on satellite imagery or airplane-based aerial photography, which can be costly, of limited availability, and of restricted resolution. These factors limit the usefulness of such imagery for detailed shoreline-change measurements that require frequent observations with high spatial accu- racy. Easily deployed balloon-based photography systems can provide high spatial and temporal resolution images at relatively low cost. This study used an Aerostat balloon photography system along with real-time kinematic (RTK) GPS to observe subannual changes in the shoreline position of the Albemarle-Pamlico Estuarine System (APES), North Carolina, USA. The fine (0.03 m-pixel) resolution of Aerostat images is ideal for mapping shoreline areas although limited in spatial extent. Features digitized from these images compare well in position (0.5 ± 0.5 m) and accuracy (± 0.4 m) to in situ RTK-GPS surveys. The balloon system is best used concurrently with RTK-GPS surveys to obtain the highest possible georectification accuracy. Results demon- strate that this method is well suited to high-accuracy analysis of shoreline positions over short timescales (annual to subannual), and that the balloon images provide a valuable spatial context for any measured changes. Preliminary analysis of shoreline change across the APES highlights great spatial and temporal com- plexity. Annualized rates of change reached >30 m/y, but average net changes were modest for survey periods (–0.5 m to 0.04 m). Tropical systems (e.g., Hurricane Earl) can be key drivers of the observed shoreline response, and the associated sediment dynamics likely have important ecological (e.g., submerged-aquatic-vegetation and water quality) ramifications.
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