Based on the perspective of the applied social sciences, this article addresses the meaning of risk, disaster and vulnerability, considering that they need to be understood and incorporated into the planning guidelines and actions for the São Paulo Macrometropolis in the context of climate variability. To ensure a deep understanding of what is called social construction of risk, it is necessary to consider the physical aspects of a given geographical space, since it is in this space that different forms of land use and occupation are promoted by society, within a given political and economic conjuncture. Among the several anthropogenic interventions the São Paulo Macrometropolis has undergone, this article addresses the problem of the floods that affect the region, focusing on areas occupied by low-income groups in urban peripheries.