Assessment of Precipitation Deficit in the São Francisco River Basin From 1998 to 2018

This work presents an assessment of the precipitation deficit in the São Francisco River Basin (SFRB) based on temporal, seasonal and regional analyses of two decades of precipitation data products derived from satellite missions launched since 1997. The temporal analyses were performed by means of three 3-month SPI time series, consisting of 250 values each derived from TRMM, CHIRPS and PERSIANN-CDR estimates. Seasonal and regional analyses were made with differences in precipitation amounts averaged between the last decade, spanning from January 2008 to December 2018, and the decade before that one, spanning from January 1998 to December 2007, for each grid cell over the domain of the SFRB. The result from the temporal analysis shows that the SFRB experienced longer and drier periods in the decade 2008-2018. The results of the seasonal and regional analyses suggest that precipitation deficit was stronger during the summer; and that the upper part of the SFRB was the most impacted by the precipitation deficit occurred over the past two decades.