Abstract
The present study determined homogeneous regions of mean annual precipitation in the Tapajós River basin, using Ward’s hierarchical clustering method, using physical-climatic variables such as: location (latitude and longitude), altitude and mean annual precipitation (PMA). Three homogeneous regions of precipitation were defined, which were validated by the Silhouette index. Nonparametric tests (Mann Kendall, Spermann and Sen Estimator) were applied to analyze the precipitation trends in each of the formed regions. The tests indicated that there is a positive trend in the PMA data in the region composed by the sources of the basin, on the other hand, in the central and the exudation regions there were no positive or negative trends in the monitored data, that is, the series have statiomarity. The determination of these homogeneous regions of precipitation is an important contribution to the understanding of the climatic behavior in the river basin, and can help in the management of water resources.
Keywords:
cluster analysis; nonparametric; climatic variability
