Floods in Southern Brazil: trends and hydroclimate changes

Climate change has become one of the most significant challenges of the 21st century and although there is uncertainty surrounding the scale, scope and, pace of climate change, it is safe to say that all people are exposed. This climate crisis has a strong effect on weather patterns, such as an increase in the frequency and magnitude of adverse events, such as floods and intense rainfall. The number of people affected by these events has grown exponentially over the years and forecasts indicate that the damage caused will increase significantly in the coming years. In southern Brazil, the disasters that cause the most deaths are those of hydrometeorological origin, for example, the event that occurred in May 2024, which affected another 1.4 million people and caused 95 deaths. The lack of planning and the occupation of areas at risk of flooding end up increasing disasters, especially in cities, where more than 85% of the population lives in the South of Brazil, the most populated area. In this context, the study proposes to investigate the incidence, magnitude and, trend of occurrence of disasters associated with floods and intense and extreme rains in the South of Brazil, more specifically in the states of Rio Grande do Sul, Santa Catarina and, Paraná. The methodological procedures included the survey and analysis of spatial and temporal data on hydroclimatic disasters, associated with flooding and extreme precipitation, from the Integrated Disaster Information System S2iD, a platform of the National System and Protection and Civil Defense, of the Ministry of Integration and Regional Development of Brazil, from January 1991 to December 2023. The research results indicated the most affected cities, number of people affected, damages, estimated economic losses and, the trend shown in the evolution of such disasters. Research knowledge provides support for decision-making and management and planning actions, in order to prevent and mitigate the occurrence of disasters, in the search for sustainable and resilient cities.