iCoast – Did the Coast Change?: Storm-impact model verification using citizen scientists

The USGS provides model predictions of severe storm impacts prior to landfall based on pre-storm morphology and predicted total water levels, including waves and surge. Presented in near real time on the USGS Coastal Change Hazard Portal, they provide coastal residents, scientists, and emergency managers valuable coastal response information. iCoast – Did the Coast Change?, an online tool for comparing pre- and post-storm photography, allows volunteer citizen scientist help researchers classify storm impacts through aerial photography. Using spatially matched pre- and post-storm image pairs from Hurricane Sandy, iCoast users identified the coastal processes seen in each image. These classifications were compared to the predictive model probabilities just prior to Sandy’s landfall. User classifications agreed with the model predictions with a high degree of confidence for dune erosion and overwash. However, for inundation, user classifications, limited to observations of island breaching, were less confident and should be used with caution