DREAM: a distributed model for runoff, evapotranspiration, and antecedent soil moisture simulation

Abstract. The paper introduces a semi-distributed hydrological model, suitable for continuous simulations, based upon the use of daily and hourly time steps. The model is called Distributed model for Runoff, Evapotranspiration, and Antecedent soil Moisture simulation (DREAM). It includes a daily water budget and an "event scale" hourly rainfall-runoff module. The two modules may be used separately or in cascade for continuous simulation. The main advantages of this approach lay in the robust and physically based parameterization, which allows use of prior information and measurable data for parameter estimation.

The proposed model was applied over four medium-sized basins in southern Italy, exhibiting considerable differences in climate and other physical characteristics. The capabilities of the two modules (daily and hourly) and of the combined runs were tested against measured data.