Variations in Soil Erosion Resistance of Gully Head Along a 25-Year Revegetation Age on the Loess Plateau

Abstract

The effects of vegetation restoration on soil erosion resistance of gully head, along a revegetation age gradient, remain poorly understood. Hence, we collected undisturbed soil samples from a slope farmland and four grasslands with different revegetation ages (3, 10, 18, 25 years) along gully heads. Then, these samples were used to obtain soil detachment rate of gully heads by the hydraulic flume experiment under five unit width flow discharges (2–6 m3 h). The results revealed that soil properties were significantly ameliorated and root density obviously increased in response to restoration age. Compared with farmland, soil detachment rate of revegetated gully heads decreased 35.5% to 66.5%, and the sensitivity of soil erosion of the gully heads to concentrated flow decreased with revegetation age. The soil detachment rate of gully heads was significantly related to the soil bulk density, soil disintegration rate, capillary porosity, saturated soil hydraulic conductivity, organic matter content and water stable aggregate. The roots of 0–0.5 and 0.5–1.0 mm had the highest benefit in reducing soil loss of gully head. After revegetation, soil erodibility of gully heads decreased 31.0% to 78.6%, and critical shear stress was improved by 1.2 to 4.0 times. The soil erodibility and critical shear stress would reach a stable state after an 18-years revegetation age. These results allow us to better evaluate soil vulnerability of gully heads to concentrated flow erosion and the efficiency of revegetation.

A Field Study for the Effects of Grass Cover, Rainfall Intensity and Slope Length on Soil Erosion in the Loess Plateau, China

“…Quantifying the impacts of slope length and grass cover on soil erosion showed that the impact of grass cover on soil loss was stronger than that of the slope length, which is similar to the results of Bircher et al [47]. The effects of the interference of the grass canopy and the change of root system on soil properties also hold positive significance for the control of soil erosion [48]. The above-ground part of vegetation has been harvested or removed; the root system of the vegetation still exerts a good control effect on soil erosion [49].…”

Effects of grass density on the runoff hydraulic characteristics and sediment yield in gully headcut erosion processes

“…The velocity showed multiple peak and valley trends over time. The soil on the bare tableland was easily eroded (Chen et al, 2020; Guo et al, 2018), and the soil surface was easily washed by runoff to reshape its topography (Samani et al, 2016; Wells et al, 2010). This process caused the topography of the tableland to be uneven.…”

The Influence Mechanism of Freeze-Thaw on Soil Erosion: A Review

“…Soil erosion occurred in areas where intense interactions among strata at the surface of land and environmental factors interact including water, wind, freeze-thaw, gravity, etc. [5][6][7]. Freeze-thaw erosion was the result of frequent changes in temperature, resulting in changes to soil and rock physico-chemical properties and occurs to a greater extent at high altitudes and latitudes in cold regions [8,9].…”