Exploring coupling effects of rainfall and surface roughness on the sheet flow velocity  

作　　者：Enshuai Shen Gang Liu Qiong Zhang Chenxi Dan Chang Liu Hairu Li Ya Liu Xueming Qu Xiaolin Xia Dandan Liu Zhen Guo Xining Zhao 

机构地区：[1]State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,College of Soil and Water Conservation Science and Engineering(Institute of Soil and Water Conservation),Northwest A&F University,Yangling,712100,China [2]Institute of Soil and Water Conservation,Chinese Academy of Sciences and Ministry of Water Resources,Yangling,712100,China [3]Key Laboratory of Water Conservancy and Water Resources of Anhui Province,Bengbu,233000,China [4]Sichuan Huabiaoce Testing Technology Co.Ltd.,Chengdu,610097,China

出　　处：《International Soil and Water Conservation Research》2025年第1期164-176,共13页国际水土保持研究(英文)

基　　金：jointly supported by the National Natural Science Foundation of China(No.42277344 and U22A20613);the Natural Science Basic Research Plan in Shaanxi Province(No.2024JC-JCQN-39);the Natural Science Foundation of Anhui Province(No.2308085US14);the Foundation of Anhui Province Key Laboratory of Water Conservancy and Water Resources(No.2023SKJ03).

摘　　要：Accurately describing the path of sheet flow(SF)is crucial in soil erosion.Raindrop impact and underlying surface conditions can affect the SF velocity by changing the velocity profile.However,since this information is rarely known,the estimation of SF velocity is inaccurate.A series of upstream inflow and rainfall experiments were carried out on an impermeable flume to determine the coupling effects of rainfall and rough bed surfaces on the SF velocity and correction factor(α).The results showed that the roughness of the bed surface had a more pronounced effect on reducing the mean velocity compared to the surface velocity in both cases with and without raindrop impact.The raindrop impact notably reduced the flow velocity near the water surface,while the mean velocity slightly decreased or remained almost constant with increasing rainfall intensity.The reduction in SF velocity can be explained by the combined effects of the roughness reducing the mean velocity(up to 33.52%)and the raindrop impact reducing the surface velocity(up to 25.43%).In addition,α was not a constant when the SF was subjected to raindrop impact.The rainfall was found to increase α,while the roughness of the bed surface reduced α for all cases.Finally,a model was created to forecast α based on the ratio of water depth to roughness height,hydraulic slope,and rain Reynolds number.The results are valuable in soil erosion by providing accurate a for estimating the surface and mean velocities of SF.

关 键 词：RUNOFF Erosion assessment Correction factor Hillslope hydrology Hydraulic parameter 

分 类 号：S157.1[农业科学—土壤学]