XING Hang, CHEN Xiaoyan, HAN Zhen, et al. Comparation of Hydrodynamic Characteristics and Flow Resistance Under Rill Erosion Between Saturated and Unsaturated Loess Soil[J]. 2018, 32(3): 92-97.
DOI:
XING Hang, CHEN Xiaoyan, HAN Zhen, et al. Comparation of Hydrodynamic Characteristics and Flow Resistance Under Rill Erosion Between Saturated and Unsaturated Loess Soil[J]. 2018, 32(3): 92-97. DOI: 10.13870/j.cnki.stbcxb.2018.03.015.
Comparation of Hydrodynamic Characteristics and Flow Resistance Under Rill Erosion Between Saturated and Unsaturated Loess Soil
The hydrological condition of the near surface plays a vital role in the slope soil erosion process. The characteristics of soil erosion in saturated soil were different from that in unsaturated loess soil. In the study
loess soil was adopted in the well-defined rill simulation scouring experiment to explore the different hydrodynamic characteristics and flow resistance between saturated and unsaturated soil conditions. Results showed that the rill flow velocity of saturated soil had good power function with slope gradient and flow rate
and the slope gradient had a greater impact on the velocity. The rill flow velocity of saturated soil was about 1.17 times that of unsaturated loess soil
while the friction resistance of slope surface under saturated state was only 70.3% compared with that in unsaturated condition. Under the same conditions
the rill flow energy and sediment concentration of unsaturated soil were much lower than those of saturated soil. With the increase of rill flow energy
the sediment concentration of both kinds of soil showed a logarithmic growth
and the peak value of rill flow sediment concentration was stable at about 400 and 280 kg/m3
respectively. Saturated and unsaturated loess soil erodibility parameters were 0.088 and 0.057 kg/(m2·s)
and the critical shear stress were 0.773 and 1.561 Pa correspondingly
indicating that saturated soil was much easier to be dispersed and eroded by water.
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