A Field Quantification of Soil Erosion Processes at Chinese Black Soil Hillslopes under Successive Overland Flow Scour Events in Summer and Spring Seasons

• Published in: Eurasian soil science Vol. 55; no. 12; pp. 1920 - 1929
• Main Authors: Shen, H. O., Hu, W., Wang, D. L., Wu, J. L., Huang, Z. Y.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.12.2022; Springer; Springer Nature B.V
• Subjects: Agricultural production; Conservation of Soils; Degradation; Drainage patterns; Earth and Environmental Science; Earth Sciences; Environmental quality; Erosion control; Flow rates; Flow velocity; Geotechnical Engineering & Applied Earth Sciences; Overland flow; Rain and rainfall; Rainfall; Ratios; Rehabilitation; Runoff; Runoff rates; Scour; Scouring; Seasons; Slope gradients; Soil erosion; Soil stabilization; Spring; Spring (season); Summer; Surface runoff; runoff; slope gradient; overflow tank; soil loss; natural runoff plot
• ISSN: 1064-2293; 1556-195X
• DOI: 10.1134/S1064229322601445

Soil erosion threatens soil resources, agricultural productivity, and environmental quality. However, soil erosion characteristics under successive overland flow scour events in typical seasons are still unclear. Five successive overland flow scour events with an interval of 24 h (l L min – 1 m – 2 overland flow rate lasted 60 min for each event) on natural runoff plots (20 m long and 5 m wide with 5° and 10° slopes) in summer and the following spring were conducted to reveal effects of the number of overland flow scour events, typical seasons and slope gradients on runoff and soil loss processes, total runoff, runoff ratios, total soil losses, and soil loss ratios. The results showed that forming stable drainage network needed four or even two overland flow scour events at the black soil (Phaeozems by WRB) hillslopes. The runoff rates versus run time rapidly increased, then stabilized at 35–65 L m –2 h –1 . The first two overland flow scour events obviously controlled soil erosion processes. Total runoff firstly increased and then stabilized with an increase in the number of overland flow scour event, and the values in spring were 1.35 times at 5° and 1.45 times at 10° greater than those in summer. As the number of overland flow scour event increased, total soil losses firstly increased and then decreased in summer, but gradually decreased in spring. The total soil losses significantly increased 2.80 times at 5° and 2.53 times at 10° from summer to the following spring. Furthermore, runoff ratios were 1.00–1.70 and soil loss ratios were 0.11–2.43, which illustrated that more attention should be paid to the impacts of successive overland flow scour events or rainfall events but not just one event on soil erosion. Additionally, typical summer and spring seasons had greater effects on both runoff and soil losses than those for other factors influencing soil erosion in this study. Thus, seasonal soil erosion control and the 2–4 overland flow scour events were noteworthy at the black soil hillslopes.