Seasonal beach profile variability and short to medium-term evolution of beaches in the municipality of General Alvarado, Buenos Aires province, Argentina

Coastal erosion is a significant environmental hazard in several localities of Buenos Aires province. The aim of this study was to determinate the seasonal beach variability and short to medium-term evolution of beaches in General Alvarado Municipality, and the relationship between this evolution and coastal storms. Sandy beaches with different geomorphological characteristics and human influence, were seasonally monitored by beach profiles and sediment sampling during two periods: from 1994 to 2004, and from 2013 to 2018. Wave conditions were also analyzed to identify coastal storms. The results highlight areas with different evolution trends. Beaches in the north are accreting, while in the south they are eroding. A stable condition is observed in the center area. Seasonally, the beaches are mostly erosive in autumn and winter, and accretional in spring and summer, concurring with the cycles related to seasonal wave conditions. Except for particular exceptions, periods with intense and successive coastal storms caused significant erosion processes, sediment loss and changes in beach profile configuration. The beaches showed different response and recovery time post storm events. The findings and methods derived from this kind of studies contribute to the design of mitigation and prevention policies, and for responsible coastal planning and management.