The Babitonga bay, located in the state of Santa Catarina, Brazil, is an estuarine system of great social and economic importance, that can be highly affected by climate changes effects. These effects include the water level increasing due to Sea Level Rise (SLR) that can be impact the circulation of the bay. In this work, effects in the circulation and mixing processes in the Babitonga bay due to SLR are evaluated. The Water Renewal Rate (WRR) and the Water Age (WA) are used as indicators for the evaluation of the effects. A hydrodynamic model was calibrated and validated for the year 2019, taken as a baseline scenario, and two representative scenarios of SLR due climate change, defined by the Inter-Governmental Panel for Climate Change (IPCC), for the year 2100, were analyzed. WRR and WA were calculated for the Summer and Winter periods for the year 2019, and also for four different projected scenarios for the year 2100. The renovation process is more efficient in the Summer because of the influence of the freshwater discharge. The results showed a reduction in the WRR for the year 2100, and, consequently, an increase in the WA, using the 2019 as the comparison scenario.
