Future scenarios (2021-2050) of extreme precipitation events that trigger landslides – a case study of the paraitinga river watershed, sp, brazil

Abstract

Global climate change and the consequent occurrence of extreme events will impact societies on a large-scale, with intense rainfall tending to trigger a greater number of hazards caused by climatic events, especially landslides. The incidence of this type of event is conditioned by the combination of several environmental and human factors, such as land use and cover patterns, geomorphological characteristics, and extreme climate. This study analyzed, through the classification of land use and cover and simulation of rainfall, future scenarios in the Paraitinga River watershed, in the southeastern region of Brazil. Precipitation data were used from the MIROC5/Eta model, using the scenario RCP 4.5 (Representative Concentration Pathway) from the IPCC (Intergovernmental Panel on Climate Change) and comparing data from past (1971-2000) and future (2021-2050) periods. The results estimate an increase in consecutive dry days and intense and very intense rainfall, pointing to heavy and concentrated rainfall in the future. An increase of 31.8% in accumulated precipitation over 72 hours that triggers landslides was also predicted, and this increase encompasses 41.6% of the areas of medium and high frequency of incidence of this type of geological event in the study area.