Resumo O presente estudo propõe um método para calcular as áreas de influência baseado no Método de Thiessen e considerando as linhas de cumeada do relevo. O estudo foi estabelecido para a bacia do Alto Sapucaí, a montante da cidade de Itajubá-MG, e foram usados os dados das estações de monitoramento de enchentes da Universidade Federal de Itajubá. Também foram utilizadas imagens da Shuttle Radar Topography Mission (SRTM). Com esses dados, foram traçadas áreas de influência das estações pluviométricas, por meio da junção do Método de Thiessen e das linhas de cumeadas mais próximas dessas medições de pluviosidade. Acredita-se que com isso os resultados das áreas de influência de uma estação climatológica sejam mais precisos que outros métodos recomendados pela bibliografia especializada.

Abstract This study proposes a method to calculate hydrological areas of influence based on the Thiessen method and considering the ridge line. The study dealt with the basin of the high Sapucai, upstream of the city of Itajubá-MG, and used data from flood monitoring stations of the Federal University of Itajubá as well as images of the Shuttle Radar Topography Mission (SRTM). Through the use of this data, areas of influence were traced of rainfall stations through a combination of the Thiessen method and the lines ridges nearest mountain of these rainfall measurements. It is believed that, using results of the areas of influence of a meteorological station, this method produces results that are more accurate than other methods recommended by the specialized literature.

This work brings as its main contribution the study of the phenomenon of density currents in non-stratified reservoirs, with flows in steady regimes. Flows are analyzed for a wide range of Reynolds and Richardson numbers in the entrance of the reservoir. Based on this hypothesis, a hybrid numeric model is presented considering the Reynolds Transport's Equation - focusing on the conservation for volume, mass and momentum - with the intention of obtaining three-dimensional components of velocities, reduced acceleration of gravity and geometric characteristics of currents along the reservoir. It is possible to notice in the numeric simulations, mainly, the need of complementation of the model that refers to the inclusion of the entrainment coefficient and the analysis in the unsteady regime.