Trends and Variabilities in the Historical Series of Monthly and Annual Precipitation in Cerrado Biome in the Period 1977-2010

Abstract The objective of the present study was to analyze the annual and monthly precipitation historical series of the Cerrado biome (Brazil), in order to identify local and regional trends. Different trend detection methods were used for 125 rain gauge stations throughout the Cerrado during the period 1977-2010, including LOWESS (LW), Mann-Kendall (MK), Theil-Sen (TS), and Pettitt (PT). The MK test suggested negative trends for 71% of the stations, with 14% of them statistically significant, mainly in the southerly region. Positive trends were found in 28% of the stations, where 1% was significant. The TS test suggested that, in general, the annual total precipitation in Cerrado decreased by 8,4% during the studied period. The precipitation in the dry months (JJAS) decreased in 76% of the stations, indicating an intensification of the dry season in the region. The results were consistent, suggesting a general decreasing trend in the precipitation of the biome, during the studied period.