Barrier island beaches provide important protection, but human development, loss of natural cover, hurricanes, and tropical storms have contributed to widespread beach erosion. Some coastal regions resort to jetties, shore protection structures, and beach nourishment, whereby offshore or other nearby sediment sources are mined and added to the beach. These projects are costly, and their effectiveness must be closely monitored. This article investigates the ability of photogrammetry from an unoccupied aerial vehicle (UAV) to quantify geomorphic changes of the subaerial section to a newly nourished beach. On October 10, 2018, Hurricane Michael moved up the Gulf of Mexico past Tampa Bay, coinciding with an ongoing nourishment project at Indian Rocks Beach. We conducted UAV and ground surveys before and after the hurricane passage and compared point clouds and across-shore profiles at three locations. We compare observed erosional regimes to probabilistically forecast erosional regimes and found they were only minimally present, perhaps reflecting the recent sand additions. An average volume loss of similar to 31 m(3)/m was measured across the three studied sections.

On October 10, 2018, category 5 Hurricane Michael made landfall at Mexico Beach, generating a nearly 5-m storm surge. The greater landfall area is characteristic of a cuspate headland protruding into the Gulf of Mexico for up to 50 km. The headland is composed of several barrier islands with different orientations fronting a large estuary. The hurricane-impacted areas include densely developed small beachfront communities, modestly to sparsely developed shoreline communities, mostly pristine state parks, and a completely pristine national wildlife refuge. Therefore, Hurricane Michael provides an excellent opportunity to study the impact of an extreme storm over various coastal environments with different degrees of human developments. Because of the shoreline orientation and bathymetry changes induced by the headland, the wave field associated with the hurricane is complicated, with different locations for the highest wave and the landfall site where the surge and wind speed were the greatest. Numerical wave modeling revealed two wave-focusing points along the headland where barrier-island breaching occurred. Beach-dune erosion and impact to infrastructure were examined and compared among various natural-human coastal systems. The magnitude of dune erosion was mostly controlled by the storm wave height and prestorm beach width, but the height of the prestorm dune was not a determining factor. Sedimentological characteristics of storm deposits along the barrier islands, within Apalachicola Bay, and in the surrounding coastal marsh were examined using 116 sediment cores and 40 grab sediment samples. Characteristics of storm deposits and their preservation are described for various subenvironments, including beaches, dunes, interior wetlands, back-barrier bay, and coastal marsh along the landward side of the estuary. The landward penetrations of identifiable sandy overwash deposits were less than 150 m along the barrier islands and less than 30 m along the mainland marshes. These results should have potential implications on paleostorm study.