The Elementary Dynamics Analysis of Rill Flow

摘要

The determination of the velocity in rill flow is the basis of studying the soil erosion. The velocity of rill flow is influenced by flow discharge, sediment concentration, underlying soil and so on. Under the steady discharge, by assuming the resistance of viscosity is directly proportional to the velocity of flow, the dynamics equation of rill flow is deduced. By nonlinear simulation of the experiment data, we obtained functions between velocity of flow and time, the friction coefficient and erosion intensity, and the viscosity force and sediment concentration in flow. The simulating procedure and results showed that the model is feasible when the velocity of flow is lower. Velocity of flow is mainly affected by slope and sediment concentration when slope and texture of soil are different. The steeper the slope is, the more time the velocity needs to achieve steady. When the friction between water flow and underlying soil is bigger than soil anti-erodibility, sediment concentration in rill flow will increase accordingly.