Hydrological simulation using the SWAT model: the case of Kalamas River catchment

The study aims to accurately simulate the hydrological regime of Kalamas River catchment, located at Epirus, NW Greece. To that end, the Soil and Water Assessment Tool was implemented, for the time period 1985-2004. The hydrological calibration was carried out by (manually) adjusting groundwater and soil parameters. The model's performance was evaluated on an annual and monthly time step, at the outlets of its (two) comprising subcatchments, based on the convergence between simulated and observed (measured by the Greek Public Power Corporation) discharges. A thorough statistical analysis was conducted, using a number of different indices (Nash-Sutcliffe efficiency, root mean square error, mean absolute error, rho and sigma/range). Overall, the values of all indices were quite satisfactory, approaching the optimum performance numbers, a fact denoting that the simulation of the catchment's hydrological regime was successful, not only in terms of total runoff produced within the simulated period but of the intra- and inter-annual variability as well.