Estimation of wind-wave induced erosion rates in wetlands on Galveston Island based on UAV photogrammetry

Wetlands within the Galveston Bay system have been eroded at a rate close to 1.0% per year during the 2000s. Waves impinging on the salt marsh edge are generally considered to be a major cause of erosion. According to previous studies, there is a high correlation between wave energy flux and erosion rate at the wetland edge. Evaluation of the position of the salt marsh edge before and after high wind events can potentially reveal notable erosion. Recently, photogrammetry by Unmanned Aerial Vehicle (UAV) is drawing attention as an efficient and low-cost way to survey the field in order to obtain topographical information. In the study, surveys by GPS equipped UAV were performed to measure the edge of wetlands in Galveston Island. By comparing generated wetlands maps among measured data at different times, the topographical difference between the measurement was analyzed and the erosion rate was calculated.