Coastal erosion evolution in algarrobo bay and vina del mar beach, central chile between 1986 to 2020 with satellite images (landsat 5, 7, 8 and sentinel 2)

The coast of Chile due to its location between two convergent plates is one of the most affected by extreme events of great magnitude, earthquakes followed by Tsunamis (1985-2010-2015), very strong ENSO events 1997-1999; 2015-2016, and increased coastal storms since 2015. To understand how these events, transform the area under study, coastal erosion dynamics were analyzed over a 34-year period at Algarrobo and Vina del Mar beaches in the Valparaiso region. We used the SHOREX system developed in Python, to extract shoreline. The WaveWatch III modeling system was developed by NOAA/NCEP, to simulate waves Pacific-wide, collected data on satellite revisit days, and quantified erosion rates using Digital Shoreline Analysis Systems tools. Satellite images were used to determine the impact of the different sources of beach transformation. Algarrobo beach shows erosion processes in 80% of its coastline with rates of up to 4.5 m/y. Currently, erosion processes are stronger in summer than in winter.