Impacts of climate change on coastal erosion and marine flooding in Rio de Janeiro city, Brazil

The environmental impact of climate change on shoreline erosion and marine flooding pose major challenges for public managers, especially in large coastal cities in Brazil. A significant portion of coastal cities have been protected by riprap structures against natural disasters and also by human action. Increasing storm surges observed in virtually all seasons of the year will allow higher waves to reach avenues and urban areas more frequently, requiring public managers to expand coastal protection structures. This article identifies and quantifies areas subject to beach retreat (coastal erosion) on open-ocean beaches in Rio de Janeiro city. The procedures consisted of acquiring images with moderate spatial resolution of 30.0 m from the sensors of the Landsat 5 (TM), Landsat 7 (ETM+), Landsat 8 (OLI) and Landsat 9 (OLI-2) satellites, referring to the years 1984, 1994, 2004, 2014, and 2023, supplemented by information on tides and wave climate obtained at the time of satellite passage. Results obtained suggest varied granulometric patterns, an increase in the number of storm waves and processes of stability and erosion shoreline in the last 40 yrs. The adoption of measures to replenishment the sediment stock on eroding beaches is necessary due to ongoing climate change.