EGU21-4363
https://doi.org/10.5194/egusphere-egu21-4363
EGU General Assembly 2021
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Regulation and Critical Threshold of Grass Cover on Slope Runoff in LoessHilly Gully Region under Artificial

Qiufen Zhang1, Xizhi Lv1, Rongxin Chen2, Yongxin Ni1, and Li Ma1
Qiufen Zhang et al.
  • 1Yellow River Institute of Hydraulic Research, Key Laboratory of the Loess Plateau Soil Erosion and Water Loss Process and Control of Ministry of Water Resources, China (qfzhang2017@126.com)
  • 2North China University of Water Resources and Electric Power

The slope runoff caused by rainstorm is the main cause of serious soil and water loss in the loess hilly area, the grassland vegetation has a good inhibitory effect on the slope runoff, it is of great significance to reveal the role of grassland vegetation in the process of runoff generation and control mechanism for controlling soil erosion in this area. In this study, typical grassland slopes in hilly and gully regions of the loess plateau were taken as research objects. Through artificial rainfall in the field, the response rules of slope rainfall-runoff process to different grass coverage were explored. The results show that: (1) The time for the slope flow to stabilize is prolonged with the increase of vegetation coverage, and shortened with the increase of rainfall intensity; (2) At 60 mm·h −1 rainfall intensity, the threshold of grassland vegetation coverage is 75.38%; at 90 mm·h −1 rainfall intensity, the threshold of grassland vegetation coverage is 90.54%; at 120 mm·h −1 rainfall intensity, the impact of grassland vegetation coverage on runoff is not significant; (3) the Reynolds number and Froude number of slope flow are 40.07‒695.22 and 0.33‒1.56 respectively, the drag coefficient is 1.42‒43.53. Under conditions of heavy rainfall, the ability of grassland to regulate slope runoff is limited. If only turf protection is considered, about 90% of grassland coverage can effectively cope with soil erosion caused by climatic conditions in loess hilly and gully regions. Therefore, in loess hilly areas where heavy rains frequently occur, grassland's protective effect on soil erosion is obviously insufficient, and investment in vegetation measures for trees and shrubs should be strengthened.

How to cite: Zhang, Q., Lv, X., Chen, R., Ni, Y., and Ma, L.: Regulation and Critical Threshold of Grass Cover on Slope Runoff in LoessHilly Gully Region under Artificial, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-4363, https://doi.org/10.5194/egusphere-egu21-4363, 2021.

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