Overland flow hydrograph in ungauged Catchment around Mosul city

ABSTRACTFive catchment areas around Mosul city have been selected ( Khoser , West of Talkief , north of Qayara , Rabeea , and Badosh ) , there were no gauging station for the surface runoff measurements. Unit hydrograph of ( 3 hr ) duration by using three models , Nash , Clark , and Saint-venant are used to draw the hydrograph. The results obtained showed that the Nash and Clark models gave closed results while the ratio between the peak discharge of Saint-venant to peak discharge of Clark and Nash are ( 2.5-27.4 ) , ( 1.14-36.23 ) respectively for different catchment.Key words : IUH ( instantaneous unit hydrograph ) , Nash and Clark models , Ungauged catchment.