Projeção de vazão para a bacia hidrográfica do rio São Francisco sob 9 cenários de mudanças climáticas SSP-RCP

Abstract

Scenarios are tools that help to understand long-term consequences and make short-term decisions. They also allow researchers to explore possible different realities. Although hidrical resources plans have been using them without attending a standard a central ideal is observed in respect of bigger or smaller water availability or keeping the same behavior of demand. It is known that land use and cover changes may increase or decrease water availability. Between de techniques applied do measure this influence the hydrological modelling shows itself as an efficient tool. In this context flow projections were produced under the SSP (Shared Socioeconomic Pathways) scenarios which contain five possible social, economic, environmental, and technological development tendencies associated with the RCP (Representative Concentration Pathways) scenarios, commonly used by the scientific community to evaluate climatic changes. The hydrological model MGB-IPH (Modelo de Grandes Bacias) developed by the Instituto de Pesquisas Hidráulicas (IPH) from the federal university of Rio Grande do Sul were applied at the São Francisco River basin. Projections of land use and cover produced under the SSP-RCP association from 2015 to 2100 and precipitation projections under the 2.6 and 4.5 RCP scenarios were used as links between the studied scenarios and the MGB-IPH. The simulation efficiency was evaluated by the Nash and Sutcliffe Coefficient (R²) and Root Mean Square Error (RMSE). The smaller water availability scenario was the SSP2-RCP2.6 which represents the current behavior with a 2,6% Q90 increase. The bigger water availability scenario was the SSP4-RCP4.5 with a Q90 increase of 16%. It is possible to conclude that in the scenarios where the environmental degradation was more expressive there was a smaller water availability and in the scenarios that consider good environmental systems management, the availability was bigger.