Using Airborne and UAS Aerial Images to Evaluate Coastal Change and Impacts to Archaeological Sites Along Loíza’s Coast, Puerto Rico

The vulnerability to erosion of Loíza’s coast is known among the local and scientific communities. Archaeology sites are distributed along or near the coastal area under the risk of coastal erosion. The main goals of this research were to identify areas with accretion or erosion along Loíza’s coast and its possible impacts to archaeological sites. Aerial images from 1930 were geometrically corrected. Two periods of forty years (1930–1970 and 1970–2010) were evaluated. The wet/dry waterline of the shoreline was digitized or provided. Digital Shoreline Analysis System (DSAS) was applied to calculate the distances between each shoreline. UAS aerial images and fieldwork applications were combined to evaluate the state of the coast in 2018. Preliminary results showed that the period, from 1930 to 1970, had more erosion rates than the second period in specific areas. Areas with higher erosion rates from 1970–2010 showed erosion in the present after hurricane Maria.