The storm of catastrophic proportions that hit the coast of São Paulo over the weekend caused incalculable damage to the affected families and cities. At least 46 people died and dozens are missing. It was the heaviest rainfall ever measured in Brazil. A phenomenon considered of “great danger” by the National Institute of Meteorology (Inmet).
Although the climatic event represents a record, it was not necessarily the strongest that has ever occurred in the national territory. There are reports of similar storms, although they have not been measured. However, to find something like this, one has to go back decades in time. What raises the alarm now, in addition to the intensity, is the recurrence of these disasters, which is increasing.
In an article published by MetSul, meteorologist Luiz Fernando Nachtigall makes a historical report on the subject. He explains that the volumes of water that hit the coast of São Paulo are rare in the entire planet and are usually linked to passages of tropical cyclones, which did not happen in São Paulo.
There were 680 millimeters in Bertioga and 626 millimeters in São Sebastião, the most affected places. In other municipalities in the region, such as Guarujá, Ilhabela, Ubatuba, Caraguatatuba, Santos, Praia Grande and São Vicente, it rained less, but still above 100 mm/day, which is already considered high risk by Inmet.
:: Coast of SP had the highest volume of rain ever recorded in the country ::
“It is very possible that, in the past, there have already been larger amounts of rain without having been measured to document it. Bertioga’s data is, therefore, the largest rainfall ever recorded and documented in Brazil, but not necessarily the largest that has ever occurred” , says Nachtigall.
About a year before last weekend’s event in São Paulo, the city of Petrópolis, in Rio de Janeiro, was hit by a storm that totaled 534.4 millimeters in 24 hours, with consequences that last until today.
Also according to the article, the previous official record was observed in 1991, when it rained 404.8 millimeters in 24 hours in the capital of Santa Catarina, Florianópolis. There is also unofficial data on a storm that hit the São Paulo municipality of Biritiba Mirim in 1947, with an accumulated 622.5 millimeters of water.
:: One year later, marks of the destruction caused by the rains still remain in Petrópolis ::
“In fact, it is something that is happening more frequently”, says climatologist and meteorologist, José Marengo, general coordinator of Research and Development at the National Center for Monitoring and Alerts of Natural Disasters (Cemaden).
According to him, it is important to come up with solutions to avoid disasters, which are the result of the climatic event and the vulnerability of the population in risk areas.
“This threat is increasing all over the world as a consequence of global warming. Climate risk is increasing at present and in the future, with climate change, it may be greater. We need to be prepared. If we cannot avoid these extreme events, at least we can prepare the population to be aware that intense rains can cause disasters and kill.”
Marengo points out that more than 24 hours before the storm, Cemaden had alerted civil defense and public authorities about the risk. In several locations on the planet, informed forecasts are sufficient for the public authorities to put into practice actions to alert and even remove the population.
ICLEI’s Resilience and Low Carbon Coordinator, Keila Ferreira, also notes that disasters are becoming more frequent. She points out that protecting the population in situations of this nature requires objective and integrated planning, which dialogues with policies for climate change, social development and human rights.
“We understand that events are coming with much greater potential. We are aware of the frailties of urban infrastructure, which do not have the capacity to respond to this. We understand that there is a much more effective monitoring system in Brazil today. That is why we understand the need to receipt of this alert and how this alert reaches the population. Because it is necessary to prepare the population for a disaster process.”
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The expert says that the actions should include forecasts and risk mapping as planning measures. It is necessary to have a diagnosis of the main threats of each city, taking into account geographic and social realities, and to implement specific policies for the regions.
These are recommendations that apply to all public authorities, but mainly to city halls, explains Santana. According to her, municipal governments must have guiding principles for prevention, preparation, mitigation, response and recovery from these disasters. Short, long and medium term goals are essential. “We know it won’t end here. We know the challenges will continue,” she says.
Editing: Nicolau Soares