Comparison of Computed and Experimentally Assessed Times of Concentration for a V-Shaped Laboratory Watershed

Abstract

AbstractIn comparison with a kinematic wave–based equation for estimation of the time of concentration, three methods, Ben-Zvi’s method, the modified Ben-Zvi method, and Izzard’s method, were applied to determine the time of concentration from the experimental hydrographs reaching an equilibrium flow state. The experiments were performed for stationary rainstorms on a V-shaped aluminum watershed in the watershed experimentation system (WES) at the University of Illinois in Urbana-Champaign, Illinois. The times of concentration determined by these three methods were compared to mathematical equations in the existing literature. It is found that the time corresponding to 89% of the maximum discharge as per the modified Ben-Zvi method yielded a generally agreeable time of concentration for the WES experimental hydrographs, while the criterion of 97% of the peak discharge as per Izzard’s method overestimates the time of concentration. It is found that Woolhiser and Liggett’s and Wong’s equations can predict t...