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

Jhones Da Silva Amorim,Rubens Junqueira,Vanessa Alves Mantovani,Carlos Rogério De Mello,Marcelo Ribeiro Viola,Nicole Lopes Bento

doi:10.4136/ambi-agua.2495

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.

Highlights

To perform studies regarding floods and droughts, analyses of different scenarios of water uses, and the streamflow prediction, among other possible applications, it is important to understand the behavior of streamflow in basins as accurately as possible (Fan et al, 2014)
As discussed by Ishak et al (2013), this step is essential to avoid mistakes that result from the changes caused by non-stationarity of the series in the estimation of streamflow for different return periods, which may compromise the application of the regionalization technique
Weibull distribution showed a good performance for several Q7 series that it is in accordance with the studies of Lopes et al (2017) and Barbosa et al (2005). This demonstrates that such Probability Density Functions (PDFs) are the most recommended for Mortes River Basin (MRB), being able to estimate the studied streamflow in this basin

Summary

Introduction

To perform studies regarding floods and droughts, analyses of different scenarios of water uses, and the streamflow prediction, among other possible applications, it is important to understand the behavior of streamflow in basins as accurately as possible (Fan et al, 2014). This understanding may be performed by analyzing the minimum reference streamflows and the frequency (or return period) of the historical floods, using historical series. The quality of the regionalization depends on the hydrological homogeneity between the sites of interest and the monitored site (Razavi and Coulibali, 2013). Beskow et al (2014) emphasized that clustering into homogeneous regions increases the success potential of the regionalization study

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