Comparison of some empirical relations in the estimated time of Concentration Ivar Watershed

摘要

Time parameters, including parameters which are of them used the most hydrologic and hydraulic models. Most commonly time parameters used in hydrology is time Concentration. Time Concentration it is duration that the water farthest point watershed reach to the outlet or point from Way River. Time concentration is required on the design of spillways, estimating flood volume, preparation flood hydrograph and many other hydrologic analysis. Until now is presented many methods for estimating time of concentration that the purpose of this study select the best method of techniques estimating the time concentration is in ivar watershed. Direction estimated time concentration on this watershed were used of five experimental method kirpich, chaw, Jianduty, Williams and California. Based on the results of the maximum and minimum time Concentration on the sub watershed I08 and I10 was obtained for method chaw 1.75 and 0.55, method California 1.88 and 0.52, method Williams 3.41 and 0.55, method kirpich 1.82 and 0.52 and Jianduty 4.78 and 0.55 h. Time concentration also watershed using any method was obtained (Kirpich, Chaw, Jianduty, williams and california), respectively, 2.01, 2.01, 4.82, 3.85 and 2.15 hours. With considering various parameters such as main water way length, subwatershed and watershed area and water way slope for kidney watershed units, the suitable concentration will be kirpich.