A comparison of baseflow indices, which were calculated with seven different baseflow separation methods

Baseflow indices for 65 North American catchments are compared, which were calculated with seven different baseflow separation methods (HYSEP1, HYSEP2, HYSEP3, PART, BFLOW, UKIH, and Eckhardt). Since the true values of the baseflow index are unknown, it cannot be said, which one of the methods gives the best estimates. However, the results of the Eckhardt method appear to be hydrologically more plausible than those of the other algorithms. Furthermore, this algorithm can be applied to hydrographs of any time step length. A simple technique for assessing the recession constant – one of the parameters of the algorithm – is presented.