Effects of Herbaceous Plants on Hydrodynamic Characters of Runoff Water, and Runoff-Yielding and Sediment-Yielding Processes on Loessial Earth-Road Surface

Abstract:

Runoff and soil losses from earthen hillside roads are a serious problem on the Loess Plateau in China. Indoor rainfall simulation was employed to investigate hydrodynamic characteristics of runoff water, and runoff-yielding and sediment-yielding processes on earth-road surfaces with different coverage degrees of herbaceous plants. The results indicated that on the road surfaces the Froude numbers and Reynolds Numbers of runoff fell into the category of supercritical flow of laminar flow and both of them decreased like the flow velocities and unit energy of water-carrying section with the coverage degrees of herbaceous plants increased. The Manning and Darcy-weisbach friction coefficients increased with the coverage degrees of herbaceous plants increased. On the earth-road surfaces with the different coverage degrees, runoff rates initially sharply increased and then stabilized with time and both following an offset hyperbola. With the coverage degrees increased, the infiltration rates of water into the earth roads gradually increased, but the runoff rates, sediment yield rates and sediment concentration all gradually decreased. The results revealed that on the earth-road surface herbaceous plants could play a favorable role in soil and water conservation and provided a theoretical basis for understanding the relations between herbaceous plants and soil erosion.

• Periodical: Advanced Materials Research (Volumes 455-456)
• Pages: 1303-1309
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.455-456.1303
• Online since: January 2012
• Authors: Gang Liu, Qiong Zhang, Shi Qing Zheng, Wen Nian Xu
• Keywords: Artificial Rainfall, Coverage Degree, Earth-Road Surface, Hydrodynamic Parameter, Run Off Reduction, Sediment Reduction

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