According to the hydrologic data of Lushi station and the region above,using the runoff model of combination between excess infiltrated runoff and saturation excess runoff,the unit flow concentration model of Nash instantaneous unit graph as well as the flow concentration model of Muskingum multi reach continuous flow routing,the paper studied the forecast method of Guxian reservoir inflow and water,then used the model to forecast the flood at the Luohe upper reaches in 2011 September,obtained satisfactory ...