The hydrological characterization of a river basin is of extreme importance for the adequate accomplishment of the management of the water resources, as well as for the planning of activities that suffer interference of the oscillations of variables like rainfall and flow. The sub-basins of Rio Negro and Rio Solimões stand out in the sub-basins of the Legal Amazon because they present great contributions in terms of flow to the Amazon River, with average discharge of approximately 32,000 m³ / s and 100,000 m³ / s, besides having good Spatialization of rainfall and fluviometric stations throughout their areas. This research consists in the hydrological characterization of these sub basins with the use of 31 years of precipitation data (1984-2014) and in the evaluation of the rainfall behavior as a function of the flow to identify the lag periods between the maximum rainfall and flow Stations. For this, information from ANA's National Hydrological Information System (Hidroweb) and ArcGis 10.1 software was used to carry out the necessary surveys. After obtaining the results, it was verified that the Solimões River sub-basin presented better flow monitoring than the Rio Negro sub-basin, however, the pluviometric records presented better monitoring in the Rio Negro area, despite all The rainfall stations presented failures. To fill these gaps, the Regional Weighting Method with Linear Regression was used. After acquisition of this information, isoietas maps were elaborated by the Linear Ordinary Kriging interpolator, being possible to calculate the water slides and the precipitated volume in each region. Ward's hierarchical method was used to create homogeneous rainfall regions in the delimitations selected in this study, and it is possible to identify areas with higher and lower rainfall indices in the maps elaborated with the use of the Linear and Inverse Ordinary Linear Kriging interpolator (IDW); In addition, the sensitivity analysis done every 5 years allowed us to infer that there was little rainfall variation over the 31 years studied, so data from the most recent 5 years (2010-2014) are able to represent all the information in the series Of this study. The temporal variation of the precipitation was analyzed annually, being possible to verify that the ENOS phenomenon is related to the pluviometric behavior of the two areas, occurring increase of the pluviometric indices in years of La Niña and reduction in years of El Niño, however, it is not possible That this phenomenon is the main enhancer of these variations. The Mann-Kendall and Spearman tests were used to evaluate trends in the time series for 31 years of rainfall data, considering a significance level of 5%, in which there was no trend or abrupt variations in the data series. To evaluate the relationship between rainfall and flow, simple hydrograms were elaborated, with the ordinate axis composed of rainfall and flow data in mm and the abscissa axis, composed by the time series, in years. This analysis allowed to verify that there is similarity in the behavior of the stations depending on their specialization along the sub basins, which presented higher pluviometric indexes between the months of December to June, in some cases prologando up to the month of August.
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