Analysis of extreme rainfall and landslides in the metropolitan region of the Paraiba do Sul River Valley and North Coast of Sao Paulo, Brazil

Abstract

Hydrological and geological disasters triggered by heavy rainfall led to major social, and economic impacts and loss of human lives. This scenario may be worsening due to climate change and the increases in the frequency and intensity of extreme rainfall events. Intense rainfall represents the hazard in terms of risk. This hazard, combined with the vulnerability and exposure of populations and the places where they live, determines the risk of disasters. Thus, our objective is to analyze the climatology and trends of extreme rainfall in the Metropolitan Region of the Paraiba Valley and North Coast of Sao Paulo (RMVPLN). The results indicate that there is an increase in frequency and intense rainfall indicators, mainly on the coast of São Paulo, resulting from positive anomalies of moisture transport and ocean winds, influenced by intense South Atlantic Subtropical High. This region is the most susceptible to the occurrence of landslides triggered by extreme rainfall as they are concentrated in areas that combine deforested areas, high slope topography, and excessive anthropic intervention. The presence of the mountainous regions increases the risk that an extreme rainfall event could trigger landslides, affecting local infrastructure and exposing the vulnerability of populations in these risk areas.