Homogeneous regions of precipitation trends across the Amazon River Basin, determined from the Global Precipitation Climatology Centre - GPCC

Abstract

Space-temporal patterns of precipitation are influenced by complex interactions between changes in climate and land cover. The Amazon River Basin has local and global impacts regarding the hydrological cycle; therefore, it is critical to understand how precipitation patterns and intensity are changing. The objective of this study was to analyze precipitation trends and form homogeneous regions of precipitation trends in the Amazon River Basin using the data set of precipitation data from the meteorological satellite Global Precipitation Climatology Center (GPCC), applying non-parametric methods (Mann-Kendall, Spearman and Sen slope) and fuzzy C-means to identify specific regions that are experiencing changes in hydrological patterns. The results show changes in rainfall behavior over time and in the intensity of events. The statistics applied to form clusters resulted in 6 well-divided homogeneous groups, each with unique characteristics. Specifically, the central-southern areas of the basin showed negative trends in precipitation (-1.17 mm/year) forming a homogeneous region (HR1), while in the northern region there was an increasing trend in precipitation (2.73 mm/year). In general, over the 37 years studied, the wetlands tended to become wetter and the dry areas drier. Other homogeneous regions presented their own results and unique characteristics, which agree with other studies