Calculation of medium precipitation using the Thiessen method and the ridge

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.