Study On The Relationship Between Sediment Transport Rate And Soil Detachment Rate Of Rill Flow On Colluvial Deposit Slop Of Benggang

To explore the relationship between detachment rate and sediment transport rate of the colluvial.The soil of colluvial from Anxi country of Fujian Province was used and different slopes(15°,20°,25°,30°,35°),flow rates(0.56 × 10-3 m2/s,1.11 × 10-3 m2/s,2.22 × 10-3 m2/s,3.33 × 10-3 m2/s)as well as the sediment transport rates(0%,20%,40%,60%,80%,100%)were set.This study investigated the sediment transport capacity and detachment within different hydraulic condition and the response of detachment rate to sediment transport rate.Then simulated the sediment transport and detachment capacity through the response equation and discussed the accuracy.The conclusions of this study were as follows:(1)Sediment transport capacity increased with flow discharge at different slope gradients which could be represented by liner equation;In addition,the growing range increased with the flow discharge and slope gradients.The sediment transport capacity of rill flow increased with different slope gradients at flow discharge and could be adequately described by power equation;Moreover,the growing range increased slowly.The sediment transport capacity closely related to the interaction of slope and flow under different hydraulic condition.And the sediment transport capacity(Tc)factor model is a binary power function expressed by slope S and flow q:Tc =2 746.18S0.62q1.05.The stream power was most closely related to sand transport capacity of the rill flow.Tc=0.30?-0.03 was used as the dynamic model for the sediment transport capacity of the rill flow.(2)The increased detachment capacity with flow discharge at different slope gradients,and could be represented by power equation;In addition,the growing range increased with the flow discharge;Detachment capacity of rill flow increased with different slope gradients with flow discharge and which could be described by power equation respectively.Moreover,the growing range increased with the slope gradients.The soil detachment capacity of colluvial all closely related to the interaction of slope and flow under different hydraulic condition.And the detachment capacity(Dc)factor model is a binary power function expressed by slope S and flow q:D,=515.86S0.86q0.90.The flow velocity and stream power were most closely related to the detachment capacity of the rill flow.Dc=0.12?-0.02 or Dc=2.57v-0.60 was used as the dynamic model for the sediment detachment capacity of the rill flow.(3)The detachment rate of the rill flow on the slope surface of the colluvial decreased with the increasing of sediment transport rate,and could be described by liner equation(Dr=a-bQs).This phenomenon was corresponded to the one-dimensional liner equation which previously reported by Foster and Meyer.In addition to the slope of 35° and the flow rate of 3.33× 10-3 m2/s.the Dc simtulated values obtained from the response equations on the slope surface were high accuracy simulated.In addition to the flow rate of 3.33×10-3 m2/s,the Tc simulated values obtained from the response equations on the slope surface were low-fidelitysimulated.For different combinations,the response equation could simulate sediment transport capacity and detachment capacity of the rill flow on the slope surface of colluvium,the accuracy of former was relatively lower.