Temporal Variability and Potential Predictability of the Streamflow Regimes in the North‐Eastern Iberian Peninsula

This paper investigates the temporal variability and potential predictability of streamflow regimes in the north‐eastern Spain for the 1970–2010 period. Two different regimes are found, those characterized for having peak flows in the winter and those where this maximum appears in the spring. The main characteristic time scales of streamflows in each area are studied by singular spectral analysis (SSA). While winter streamflow regime only shows interannual variability (quasi‐oscillatory modes around 5.5 and 2.3 years), spring streamflow (2.6 and 6.6 years) also presents a decadal variability component. Based on this result, a modelling process is conducted using autoregressive moving average (ARMA) models, for interannual variability modelling, and stable teleconnections between global oceanic sea surface temperature (SST) anomalies and river flow, for decadal variability modelling. Finally, a one‐step‐ahead prediction experiment is computed to obtain forecasted streamflows. The results for winter streamflow regime modelling show a phase concordance between the raw and the forecasted streamflow time series of around 70% and a correlation around 0.7, for the validation period (2001–2010). For spring streamflow, additionally to the ARMA modelling for the interannual component, a model based on the SST has been established that involves some oceanic regions from previous seasons located, fundamentally, not only in the North Atlantic but also in the Indian Ocean. The combined model (SST + ARMA) significantly improves the prediction based on the ARMA model alone, showing a phase concordance and a correlation around 90% and 0.7 respectively. This modelling scheme provides predictability skills of the rivers from the Inland Catalan Basins at different time scales, representing an added value for water planning. Copyright © 2014 John Wiley & Sons, Ltd.