Environmental disasters are natural intense events, such as mass movements and floods, which are intensified by the society and may affect it directly and indirectly. Studies on the occurrence of these possibilities at places of human interference, that is, the risks have been growing steadily. In this study, we analyze the basin of the River Bengalas in Nova Friburgo- RJ evaluating the physical and social characteristics, using data obtained from primary form, questionnaires at the place and landscpae analysis, and secondarily to the census of 2010, historical data, physical and public politics agencies. This research used the environmental ROSS modeling (1994) and Baptista (2009) to distinguish areas of potential disasters, together with the social characteristics weighted based on Torres (1997) and ALVES (2007), and the evaluation of public policies to minimize environmental impacts. According to the environmental modeling were diagnosed three most vulnerable areas in Basin Bengalas, with the analysis of questionnaires carried out in the area, comparing them with public politics and mapping, it is remarkable that urban spaces are differentiated according to the greater or lower exposure of humans to environmental risks. It can be concluded that environmental risks are socially constructed and greater fragility of the envirnment intensifies this process. There has been a disagreement between the desire of the population to remain in place, and the action of the government on the issue of environmental impacts. The most exposed population to the risks built relations related to their community, aiming a focused effort by governments to reduce the probability of disasters, and these, in time to review the Participatory Master Plan of Nova Friburgo, should analyze the diversity of elements to minimize environmental injustices historically constituted around the city.