Modelo de previsão de vazões sazonais e interanuais

Abstract

This paper presents the results of a semi-parametric approach for forecasting seasonal to interannual streamflow for a reservoir system in Ceara State. The forecasts have a 18 months horizon, and is issued in July. The methodology employs the Principal Components Analysis for the streamflows of the reservoir system. Principal Components Regression is performed using climate indexes as explanatory variables. The strategy considers statistical forecasts of annual or seasonal streamflow totals at each of the sites, and their disaggregation to monthly or higher resolution flows using a k-nearest neighbor resampling approach in order to compute the probability of the inflows. The results were considered satisfactory with a correlation between the median of the identified distribution and the observations of 0,93. The intention is use the performed forecasts to operates a reservoir system, giving support to the water allocation process.