Journal of Applied Sciences1812-56541812-5662Asian Network for Scientific Information10.3923/jas.2009.105.112MojaddadiH.HabibnejadM.SolaimaniK.Z. AhmadiM.A. Hadian-AmriM.1200991This research has been carried out for investigation
and comparison of the amount of precision and correctness of SCS unit
hydrograph, GRAY, G.I.U.H and Gc.I.U.H models in determination of the
shape and dimensions of outlet runoff hydrograph in Navroud watershed
with 266 km^{2} area, located in Giulan Province of Iran and use
of these models for the similar watersheds and without any data. To investigate
the amount of efficiency of above-mentioned methods, first 6 equivalent
rainfall-runoff events were selected and for each, hydrograph of outlet
runoff were calculated. Then the models were compared with together, for
peak time, base time, peak flow and volume of outlet runoff and the most
efficient model in estimation of hydrograph of outlet flow for similar
regions was proposed. Comparison of calculated hydrographs obtained from
models under research and observed hydrographs of selected events showed
that SCS unit hydrograph method had the most direct agreement in three
parameters of peak time, base time and volume of direct runoff. On the
other hand, the geomorphoclimatic instantaneous unit hydrograph, with
the highest mean relative error of 16%, had highest harmony in estimation
of peak flow direct runoff.]]>Alizadeh, A.,2006Bahadori Khosroshahi, F.,1989Barkhirdari, J.,2006Bhaskar, N.R.,1997Bhunya, P.K., R. Berndtsson, C.S.P. Ojha and S.K. Mishra,2007Bonta, J.V. and R.A. Roa,1992Chow, V.T.,1964Chow, V.T., D.R. Maidment and L.W. Mays,1988Erfanian, M.,1998Ganjkhanlou,2002Ghahraman, B.,1995Ghiasi, N.,1996Ghioto, R.D.,1991Gray, D.M.,1961Habibnejad, M., M.Z. Ahmadi and H. Ganjkhanloo,2004Heshmatpour, A.,1999Heshmatpour, A., M. Saravi, A. Saaddin and M. Erfanian,2002NRCS1972Karvonen, T., H. Koivusalo, M. Jauhiainen, J. Palko and K. Weppling,1999Mahdavi, M.,2005Mobaraki, J.,2006Nash, J.E.,1958Rahimian, M. and M. Zare,1995Rezaee, A.,1994Rodriguez-Iturbe, I.,1993Rodriguez-Iturbe, I., M. Gonzalez-Sanabria and R.L. Bras,1982Rodriguez-Iturbe, I., G. Deveto and J.B. Valders,1979Sadeghi, H.R., H.R. Moradi, M. Mozayan and M. Vafakhah,2005Shahmohammadi, Z.,1994Singh, S.K.,2000USACE,2000Viessman, W. and G.L. Lewis,2003Zehtabian, Gh., A. Alipour Tomaj and M. Vafakhah,2001Zeiazinski, J.,1986Smith, M.B., V.I. Koren, Z. Zhang, S.M. Reed, J.J. Pan and F. Moreda,2004Rodriguez-Iturbe, I. and J.B. Valdes,1979