Estimativa de vazões médias sazonais em bacias sem dados hidrométricos para uso em sistemas de previsão hidrometeorológica.

Abstract

Forecasts of seasonal precipitation are available for the Brazilian northeast. These forecasts of precipitation have been used to forecast seasonal average discharge in the basins with discharge and precipitation observations. Then, there was the motivation for the development of a study for estimation of daily seasonal average discharge in basins without hydrometric observation. Statistical methods of correlation and multiple linear regressions were utilised, as well as the application of the technique of hydrologic regionalization, adapted to the estimation of annual values of the average discharge, in opposition to the estimation, usual in regionalization, of the long-term average discharge. It is proposed, in this study, a model based on the physical and hydrological characteristics of hydrographic basins, and soon after, this is applied to 13 basins inserted in the hydrographic basins of the rivers Piranha-Acu-Apodi, located in the semi-arid Northeastern Brazil. Good correlations between the observed data and the modelled values were obtained in validation tests, indicating that the proposed method is a technique that can be used in operational hydrometeorological forecasting systems.