Using historical source data to understand urban flood risk: a socio-hydrological modelling application at Gregorio Creek, Brazil

The city of Sao Carlos, state of Sao Paulo, Brazil, has a historical coexistence between society and floods. Unplanned urbanization in this area is a representative feature of how Brazilian cities have developed, undermining the impact of natural hazards. The Gregorio Creek catchment is an enigma of complex dynamics concerning the relationship between humans and water in Brazilian cities. Our hypothesis is that social memory of floods can improve future resilience. In this paper we analyse flood risk dynamics in a small urban catchment, identify the impacts of social memory on building resilience and propose measures to reduce the risk of floods. We applied a socio-hydrological model using data collected from newspapers from 1940 to 2018. The model was able to elucidate human-water processes in the catchment and the historical source data proved to be a useful tool to fill gaps in the data in small urban basins.