Impacts of biocrusts on sheet erosion and its detachment- and transport-limited processes: A case study from the Loess Plateau, China. (November 2022)

• Record Type: Journal Article
• Authors: Guo, Qi; Wang, Zhanli; Shen, Nan; Zhao, Yunge
• Is Part Of: Biosystems engineering. Volume 223(2022)Part A
• Page Start: 18
• Page End: 28
• Publication Date: 2022-11
• Subjects: Biocrusts -- Sheet erosion -- Splash detachment -- Detachment- and transport-limited -- Loess Plateau; Bioengineering -- Periodicals; Agricultural engineering -- Periodicals; Biological systems -- Periodicals; Génie rural -- Périodiques; Systèmes biologiques -- Périodiques; 631
• DOI: 10.1016/j.biosystemseng.2022.08.016
• Languages: English
• ISSNs: 1537-5110

Abstract

Abstract : Understanding sheet erosion processes and improving estimates of soil erosion on biological soil crustal (biocrustal) slopes requires a deep understanding of the factors influencing sheet erosion and its detachment- and transport-limited processes. Simulated rainfall experiments were conducted on plots of biocrust to simultaneously measure the rates of splash detachment and sheet erosion with 0%, 20%, 40%, 50%, 60%, and 80% of coverage at 90 mm h −1 rainfall intensity and 15° slope. The splash detachment rate decreased rapidly during the first 5 min of rainfall and stabilised as rainfall continued, while the sheet erosion rate increased gradually and eventually became relatively stable. The rates of splash detachment and sheet erosion decreased substantially as biocrusts coverage increased and average values of them can be effectively weakened when biocrusts coverage increased from 20% to 40%. Transport-limited processes, dynamic equilibria between detachment- and transport-limited processes, and detachment-limited processes all occurred on biocrustal slope within the same rainfall event. The mean duration of transport-limited processes was longer (16.3 min vs. 9.1 min) when bare slopes were covered by biocrusts, and the latest change in the time from transport-limited to detachment-limited processes appeared at 40% biocrusts coverage. The existence of biocrusts could effectively affect the sheet erosion and its detachment- and transport-limited processes, especially when the coverage was close to 40%. These results can improve our understanding of impacts of biocrusts on sheet erosion processes, and aid an effective way of reducing sheet erosion in arid and semiarid regions. Highlights: The effects of biocrusts on sheet erosion were explored. Detachment- and transport-limited processes occurred on biocrustal slope. Increasing biocrusts coverage reduced rates of splash detachment and sheet erosion. Biocrusts with a cover close to 40% effectively affected sheet erosion processes.