Estimation of unit hydrograph components using relationship between characteristics of available hyetographs and hydrographs in kasilian representative watershed

Different methods can be used for estimation of floods in regions facing lack of data out of which the methods leading hydrographs are able to present accurate details on floods. Information and data on rainfall and runoff are required to develop watershed unit hydrograph. Providing the unit hydrograph (UH) for all storms of a watershed is not simple and it demands plenty of time، expenses and facilities. Because of various limitations like insufficient hydrometery stations and difficulties in collecting hydrometrical data، application of the simple hydrological models based on easily accessible data seems logical and useful in order to estimate the flood hydrograph. This study was therefore aimed to provide synthetic 2h-UH using rainfall data in Kasilian watershed. Towards this attempt، 15، 19 and 12 hyetograph، UH and time relating characteristics were respectively considered for 23 storms. The relationship was investigated by using bivariate and multivariate regressions. Results showed 2h-UH could be reproduced based on hyetograph components. The results also verified the effective roles of time of occurrence of I30 and rainfall duration in simulating 2h-UH of the study watershed.