Jinshan Soil and Water Conservation Research Center, Fujian Agriculture and Forestry University, Fuzhou, China.
PeerJ. 2023 Jan 24;11:e14766. doi: 10.7717/peerj.14766. eCollection 2023.
The detachment-transport coupling equation by Foster and Meyer is a classical equation that describes the relationship between detachment and transport. The equation quantifies the relationship between sediment loads and soil detachment rates, deepens the understanding of soil erosion and provides a reliable basis for the establishment of an erosion model. However, the applicability of this equation to slopes with gradients greater than 47% is limited. In this work, the detachment-transport coupling relationship is investigated using the colluvium material of Benggang. A nonerodible rill flume 4 m long and 0.12 m wide was adopted. The slope gradient ranged from 27% to 70%, the unit flow discharge ranged from 0.56 × 10 to 3.33 × 10 m s, and the sediment transport capacity ( ) was measured under each slope and discharge combination. The sediment was inputted into the flume according to the predetermined sediment addition rate (from 0% to 100% of ), and the detachment rate ( ) under each combination of the slope and discharge was measured. linearly decreased with increasing sediment loads, which is consistent with the detachment-transport coupling equation by Foster and Meyer. The linear equations can predict the detachment capacity ( ) and well (Nash-Sutcliffe efficiency coefficient (NSE) = 0.98 for , and NSE = 0.99 for ). The detachment-transport coupling equation can adequately predict the (NSE = 0.89). However, its applicability to slopes of <47% (NSE: 0.92-0.96) was greater than that to slopes of ≥47% (NSE: 0.81-0.89), and the predicted under levels of 20% and 40% were higher than the measured values, while the predicted value under a level of 80% was lower than the measured value. In summary, the detachment-transport coupling equation by Foster and Meyer can accurately reflect the negative feedback relationship between detachments and transports along steep-slope fixed beds and is suitable for colluvial deposit research. The results provide a basis for the construction of steep-slope colluvial deposit erosion models. In the future, the study of the hydrodynamic characteristics of sediment transport processes should be strengthened to clarify the detachment-transport effect of flows through hydrodynamics.
福斯特和迈耶的离解-输移耦合方程是描述离解和输移关系的经典方程。该方程量化了泥沙负荷与土壤离解速率之间的关系，加深了对土壤侵蚀的理解，并为侵蚀模型的建立提供了可靠的基础。然而，该方程在坡度大于 47%的斜坡上的适用性有限。在这项工作中，采用崩岗岩土进行了离解-输移耦合关系的研究。采用了一个 4 米长、0.12 米宽的不可侵蚀的浅沟水槽。坡度梯度范围为 27%至 70%，单位流量范围为 0.56×10 至 3.33×10 m s，在每个坡度和流量组合下测量泥沙输移能力（）。泥沙根据预定的泥沙添加率（0%至 100%）输入水槽，测量每个坡度和流量组合下的离解率（）。随着泥沙负荷的增加，呈线性下降，这与福斯特和迈耶的离解-输移耦合方程一致。线性方程可以很好地预测离解能力（）和（纳什-苏特克里夫效率系数（NSE）为 0.98 时，为；NSE 为 0.99 时，为）。离解-输移耦合方程可以很好地预测（NSE 为 0.89）。然而，它在坡度小于 47%（NSE：0.92-0.96）的适用性大于坡度大于等于 47%（NSE：0.81-0.89），且在 20%和 40%的水平下预测的大于实测值，而在 80%的水平下预测的小于实测值。总的来说，福斯特和迈耶的离解-输移耦合方程可以准确反映陡坡固定床的离解和输移之间的负反馈关系，适用于崩岗岩土的研究。研究结果为建立陡坡崩岗岩土侵蚀模型提供了依据。在未来，应加强对泥沙输移过程水动力特性的研究，以澄清水流的离解-输移效应。
