Calibration of Maidment's Formula Coefficients for Runoff Velocity

With regard to predictions based on ungauged basins, much attention has been given to the use of the rainfall–runoff models based on the geomorphological unit hydrograph theory. One of the central points of the geomorphological theory based on a kinematic approach is to estimate the flow time function, that means to estimate the runoff velocities over basin’s hillslopes and channels. Usually were assigned constant velocities for both hillslopes and channels. The aim of this work is to investigate the behavior of the Maidment formula, which allows us to determinate a spatial distributed velocities fields instead of using two constant values of velocities. A rainfall runoff model based on width function instantaneous unit hydrograph (WFIUH) has been used.