The width of main channel would influence the water level rising rate greatly in flood events . when the discharges in main channel increased to 8000 m ' / s from 3000 m3 / s the water rising amplitude at hydrometer stations in the lower yellow river was correlative well with the exponent ( - 0 . 65 ) of main channel width and the exponent ( - 0 . 33 ) of river longitudinal slope 洪水期主槽宽度对水位涨率有较大影响，主槽流量从3000m ~ 3 s增大到8000m ~ 3 s时，下游各水文站断面水位的抬升幅度与主槽宽度的( - 0 . 65 )次方和河道纵比降的( - 0 . 33 )次方具有较好的相关关系。
