Análise de monitoramento de seca na região da bacia do rio São Francisco, utilizando o produto espacial PERSIANN-CDR durante o período de 1989 até 2018

Abstract

Precipitation plays a crucial role in the hydrological cycle and energy generation, being essential to understand extreme weather events. The precipitation measurement system using ground-based rain gauges is the most common and accurate method of measuring precipitation, however, it may have uncertainties and errors depending on the locality. Satellite-based precipitation estimation system is a possible alternative, with global or semi-global coverage and high spatial and temporal accuracy (spatial scale of 0.05° and temporal scales of 30 minutes), thus capable of generating precipitation data, but the feasibility of satellite precipitation products in capturing precipitation is a topic that needs to be studied. This study analyzes the performance of the PERSIANN-CDR product compared to data from rain gauge stations in the São Francisco River basin region. Using statistical indicators and the Standardized Precipitation Index (SPI) at various time scales, namely 1, 3, 6, and 12 months (SPI-1, SPI-3, SPI-6, and SPI-12). In the Upper and Middle São Francisco, consistent results are found in the statistical indicators and SPI, with a better ability to detect drought at larger time scales, except for SPI-12. In the Sub-middle São Francisco region, inferior performance is observed in some indicators due to low precipitation, although SPI-6 and SPI-12 have shown the best results. Finally, in the Lower São Francisco region, where there are few rain gauge stations, satisfactory results were not obtained, highlighting the need for additional studies.