Streamflow regionalization for the Mortes River Basin upstream from the Funil Hydropower Plant, MG

Abstract

Maximum and minimum streamflow are fundamental for water resource management, especially for water rights. However, lack of monitoring and scarce streamflow data limit such studies. Streamflow regionalization is a useful tool to overcome these limitations. The study developed models for regionalization of the maximum and minimum reference streamflows for the Mortes River Basin (MRB) (Water Resources Planning and Management Unit - GD2), Southern Minas Gerais State. The study used long-term streamflow historical series provided by the Brazilian National Water Agency (ANA). Previous exploratory analysis was performed, and it was observed that the streamflow series are stationary according to the Mann-Kendall test. The estimation of the streamflow for different return periods (RP) was performed by fitting Probability Density Functions (PDFs) that were tested by the Anderson-Darling (AD) test. The Generalized Extreme Values (GEV) and Wakeby were the most appropriate PDFs for maximum and minimum streamflows, respectively. The streamflow models were fitted using a power regression procedure, considering the drainage area of the watersheds as inputs. The fittings reached the coefficient of determination (R2) greater than 0.90. Thus, the streamflow regionalization models demonstrated good performance and are a potential tool to be used for water resource management in the studied basin.

Hydrological Response to Drought Occurrences in a Brazilian Savanna Basin

“…Regarding Q 7,10 (6.9 m 3 s −1 ), for the streamflow that is used as a basis for granting water resources in the region, the PDF that presented the best fitting was Wakeby, with AD equal to 0.30. Amorim et al [29] found a similar result in the Mortes River, Southeastern Brazil, demonstrating the satisfactory performance of this PDF for the Q 7 series. The SY 7,10 was equal to 2.1 L s −1 km −2 , similar to that obtained by Silva et al [6] in the Minas Gerais State.…”

“…The Q mean was obtained from the average of the daily streamflow, while the Q min and Q max were obtained from the average of the minimum and maximum daily annual streamflow, respectively. To obtain Q 7,10 , 10 PDFs fitted using the L-moments were analyzed [29]: the 3-parameter log-normal (LN3), 3-parameter Pearson (PE3), the Gumbel extreme value, the Generalized Extreme Values (GEV), Gamma, Weibull, the 4-parameter Kappa, the 5-parameter Wakeby, the generalized logistic (GLO), and the generalized Pareto (GPA). The PDF was then selected based on the best fitting according to the Anderson-Darling (AD) test.…”

At-site flood frequency analysis in Brazil

“…Moreover, Rahman et al ( 2014) assessed WAK's applicability in Australia and reached the same conclusion; thus, they recommended the use of this PDF for the probabilistic modeling of flood events in that country. Similarly, Amorim et al (2020), in a study applied to the Mortes River basin, Brazil, concluded that WAK was one of the most appropriate PDFs for probabilistic modeling of floods events.…”