Simple statistical models for relating river discharge with precipitation and air temperature-Case study of River Vouga (Portugal)

Simple statistical models were developed to relate available meteorological data with daily river discharge (RD) for rivers not influenced by melting of ice and snow. In a case study of the Vouga River (Portugal), the RD could be determined by a linear combination of the recent (P (R)) and non-recent (P (NR)) atmospheric precipitation history. It was found that a simple linear model including only P (R) and P (NR) cannot account for low RD. The model was improved by including non-linear terms of precipitation that accounted for the water loss. Additional improvement of the models was possible by including average monthly air temperature (T). The best model was robust when up to 60% of the original data were randomly removed. The advantage is the simplicity of the models, which take into account only P (R), P (NR) and T. These models can provide a useful tool for RD estimation from current meteorological data.