In recent decades, natural disasters have increased gradually, mainly due to human activity and climate change, which have contributed to the increased likelihood of these phenomena and their negative impacts on populations, especially those most vulnerable. In the case of floods, some of its causes are: the lack of urban planning, soil sealing, siltation of rivers and climate change. The impacts of this phenomenon can range from the destruction of public infrastructure, to the human and economic losses, damage to historical and cultural heritage and the environment. In Brazil, the risks of natural disasters are recurrent, but these were seen as small-scale, localized in certain regions and cities - are the extensive risks to the profile of "hidden risks", which led the authorities to neglect cultural socio-economic and political impacts of these events. However, in recent years due to the increased frequency of various "natural disasters and catastrophes," mainly caused by mass movement and floods, federal, state and municipal governments have recognized that these small, recurrent and frequent "natural disasters" generate impacts negative, which led them to consider their effects and to take effective action to identify and quantify the individual, social, economic and environmental risk, assess the vulnerability and the risk of exposed human elements, and thus develop specific policies in response to risks of natural disasters, especially those of hydrologic nature. Based on these aspects, this study aims to analyze and evaluate the strategies used by Brazil in protecting the impacts from natural events on civil society and the implementation of public policies of natural disasters floods. To assist in the understanding of these strategies, if adopted as a case study the municipality of São Luiz do Paraitinga (São Paulo) which, in 2010, was hit by a major flood due to heavy rains that caused the river overflow Paraitinga. The theme presented is multidisciplinary, it is located on the border between the Human Sciences (Sociology, Politics and Geography Science), Social Sciences (Urban Planning and Regional Law and Demography), and Exact Sciences and Earth (Earth Sciences) whose methodological approach is plural, based on the literature, documentary research and field with the use of questionnaires and interviews.

KEYWORDS: government actions - Socio disaster - prevention - risk - vulnerability.