Α Comparative Study of Conceptual Rainfall-runoff Models using Different Number of Parameters and Time Steps: Application to Plastiras Lake River basin in Thessaly (Greece)
Abstract:
In this work, via Med basin software, two different conceptual rainfall-runoff models were used i.e. a monthly time step modified simple water balance model (Medbasin-M) comprising three calibration parameters and a daily time step (Med basin-D) comprising 14 parameters. As study area was selected the mountainous Plasters lake river basin in Thessaly of a total area of 166 km2. Rainfall and potential evapotranspiration data were used as input to both models. Additionally, measured runoff values were available for performing calibration and validation stages. As calibration period for both models was chosen from October 2012 to September 2017 and as validation period from October 2017 to September 2019. The Medbasin-M with the three parameters was proved that performs satisfactorily (e.g. NSE equals 0.57 for calibration and 0.52 for validation period). Moreover, Med basin-D gave clearly better results: 1. for the simulated daily runoff (NSE 0.73 and 0.69 for calibration and validation periods respectively) 2. for the simulated monthly runoff (NSE equals 0.9 for calibration and 0.77 for validation period). In addition, a sensitivity analysis was carried out in each case, for indicating which parameters influence the most models output
