Dimensioning of reservoirs for semiarid regions using synthetic series

ABSTRACT The lack of fluviometric data for hydrographic basins affects the estimates of capacity of regularization reservoirs, important to meet water seasonal demands. The objective of this study was to evaluate the performance of methodologies based on synthetic series (SS) of streamflow for the dimensioning of regularization reservoirs in the Jequitinhonha River Basin, Brazil. The reservoir capacity (RC) was estimated with and without the association to return period, using different long-term mean streamflow rates, SS from the observed data, and estimated data by the streamflow regionalization process developed by the Instituto Mineiro de Gestão das Águas. The results obtained were compared to the RC obtained in regionalization methods of the regularization curve and regionalization of reservoir capacity. The methods that include synthetic series associated to return period presented better performance, with 25% and 15% lower overestimate and underestimate means, respectively, and estimated values closer to those that considered the observed data series. Therefore, the use of methodologies to estimate RC, using SS was adequate for the locations without fluviometric monitoring in the Jequitinhonha River Basin.