The variations of hydro-dynamic parameters(Reynolds number

Froude number

average flow velocity

water depth and resistance coefficient) of overland flows were characterized under different flow discharge

slope gradient and roughness based on flume experiments.The research results indicated that Reynolds number

Froude number

average flow velocity

water depth and resistance coefficient of the overland flows increased with flow discharge for the artificial beds with same roughness and slope gradient.Under the conditions of same gradient and flow discharge

Reynolds number

Froude number and average flow velocity of the overland flows decreased with increasing roughness

while resistance coefficient and flow depth increased.Flow discharge and slope gradient were found closely correlated with the hydraulic parameters such as average flow velocity

water depth

and resistance coefficient

which could be well described by simple power functions.Furthermore

the influences of flow discharge were dominant.