Prediction of dimensionless sediment transport capacity for loess slopes and its response to flow intensity parameters

Purpose The sediment transport capacity provides a theoretical basis for accurate prediction of soil erosion. The aim of this study is to develop a sediment transport capacity prediction model applicable to a variety of soils. Materials and methods Sandy loess and loess soil (d(50) = 0.095 mm and d(50)' = 0.04 mm) were used to conduct indoor sediment transport experiments under different hydraulic conditions. Moreover, the experimental data of cohesive soil and cohesionless sand was combined, and the response relationship between sediment transport capacity and each flow intensity parameter was analyzed through dimensionless processing. Results and discussion Results showed that the sediment transport capacity had an exponential function relationship with unit discharges and energy slopes. The sediment transport capacity also varied with the changing flow intensity parameters, and through analysis, the effective stream power was observed as an optimum predictor (R-2 = 0.9692). Considering the effective stream power and volumetric sediment concentration, this study derived a formula for calculating the sediment transport capacity. Conclusions In conclusion, this study innovatively established a prediction model of sediment transport capacity on loessial slopes though regression analysis and dimensionless method. The proposed model is capable of considering flow intensities and volumetric sediment concentration simultaneously, and has a superior applicability to both cohesive soil and cohesionless sand compared with the four main existing models.

Automated summary

This study developed a sediment transport capacity prediction model applicable to various soils through experiments and analysis. Results showed an exponential relationship between sediment transport capacity and flow intensity parameters, with effective stream power identified as the optimal predictor.