Streamflow In The Sapucaí River Watershed, Brazil: Probabilistic
Modeling, Reference Streamflow, And Regionalization
Abstract
This work aims to study the streamflow statistic patterns in the Sapucaí
River watershed, state of Minas Gerais, Brazil. This study embraces the
streamflow probabilistic modeling to determine the reference streamflow
and, later, the streamflow regionalization to improve the water
resources management. A 26-year-data series (1989 - 2014) of maximum,
average, and minimum streamflow were used. Probability density functions
were applied to the maximum and minimum daily streamflow to determine
the recurrence periods. Long-term average annual and monthly streamflow
were also calculated. Linear and non-linear regressions were adjusted
for the streamflow regionalization. The drainage area and the streamflow
equivalent to the total rainfall (with and without abstractions) were
used as predictor variables. The probability density functions that best
adjusted the maximum streamflow data set were the Generalized Extreme
Values, and for the minimum streamflow was the normal distribution.
Linear and non-linear regressions were efficient (R²> 0.90
and d Willmott> 0.97) in the regionalization process
regardless of the predictor variables. However, a small statistical
advantage was found for the adjustment of non-linear regressions that
used the predictor variables drainage area and the streamflow equivalent
to the total rainfall (without abstractions).