Elfride Anrain Lindner,Masato Kobiyama,Guillermo Nei Caprário, Universidade do Oeste de Santa Catarina, Engenharia Civil, elfride.lindner@unoesc.edu.br
Abstract
Rio do Peixe watershed, southern Brazil, has suffered natural disasters caused by excess and shortage of rainfall. Four incremental basins were studied (Pe1, 803 km2 ; Pe2, 2,018 km2 ; Pe4, 3,708 km2 and Pe4, 5,238 km2 . Historical series (28 years) of daily hydro meteorological data were used. The mean values [mm.d-1] of precipitation (P), potential evapotranspiration (ETP), real evapotranspiration (ETR) were 4.70; 2.83; 2.32 (Pe1); 4.83; 2.85; 2.63 (Pe2); 4.93; 2.90; 2.53 (Pe3); 4.95; 2.95; 2.73 (Pe4), respectively. The Tank Model, with four vertical reservoirs and twelve parameters, was calibrated and validated. The mean daily observed and calculated discharges [mm.d-1] were: 2.38 and 2.43 (Pe1); 2.20 and 2.19 (Pe2); 2.40 and 2.35 (Pe3); 2.22 and 2.18 (Pe4), respectively. The Tank Moisture Index (TMI) was created, considering the daily water storage in reservoirs 1 to 4, and use of central tendency (average and median). TMI (0-10) was applied to analyze public calamity states due natural hazards, period of 1977 to 2004. Median compared with average produced higher adjustment (floods, 84%; droughts, 90%). The present study showed that Tank Moisture Index, on daily basis, applied to extreme hydrological events, is useful for floods’ warnings, and also for droughts duration and severity analyses.
Key words: Tank Model; floods; droughts; Tank Moisture Index