Gravelly soils are made up of gravel

cobble

sand and cohesive soils. They have been widely used in engineering applications such as earth-rock dams impervious fillings and stub cutoff walls. Present researches are mainly aiming at these engineering applications; researches on fine grained soils of the loose gravelly slopes running off under rainfalls

making structures of the soils alteration and affecting their mechanical properties or even affect the slope stability

are few order to study the erosion process and features of the gravelly slope soil under rainfall conditions

this essay carried out a sort of artificial rainfall local and model experiments; and the water content and sediment content of the runoff is monitored in the experiment. Result shows that the shapes of the slope surface transformed phasicly; runoff producing rate and erosion modulus increases linearly with lengthening of slope length. Runoff quantity increases along with the time of the rainfalls with the character of hopping and fluctuating

sediment content descents adapt to the rainfall time with the character of approximate power function.