Estimativas da vazão máxima e capacidade de saturação hídrica da bacia hidrográfica do alto do rio ligeiro Em Pato Branco, PR

Abstract

The aim of this paper is to estimate the maximum flow in Upper River Ligeiro watershed (1/3 higher) using the curve number method, developed by Soil Conservation Service (SCS), by the application of the rational formula and the Ven Te Chow equation, both hydrologic methods that transform rainfall into runoff. This watershed is located in Pato Branco (latitude 26°09'52" S and longitude 52°41'44" W) covering an area of 68.26 km2. In order to get the hydrological model it was necessary the preparation of thematic maps of land use for the years 1980 and 2008. Under normal humidity conditions (NII), recurrence time of 10 years, the peak flow (rainfall 0.3 m) increased from 59.76 m3 in 1980 to 72.13 m3 in 2008. This flow is due to the impermeability of the basin in the period and agricultural crops area reducing, which consequently reduced the average rate of infiltration basin (the cultivated areas in 1980 reached 70.63% of the total watershed and in 2008 were reduced to a percentage of 51.98%).