Abstract:Abstract:[Objective] Spoil heaps, a major source of soil erosion in construction projects, feature a platform-slope structure, where platform runoff induces severe slope erosion in different inflow patterns. However, the response mechanisms of the slope erosion process to the inflow patterns remain unclear. [Methods] Artificially simulated scouring experiments were conducted with two inflow patterns (concentrated-flow and surfaced-flow) and three flow rates (4, 8 and 12 L/min), to reveal the effects of different inflow patterns on the sediment production and hydrodynamic characteristics of slope erosion. [Results] 1) The process of sediment and runoff production were the similar under both concentrated-flow and surfaced-flow. The process of runoff production exhibited a transition from jumping to stabilization, while the process of sediment production showed a rapid decrease and then a fluctuating reduction. Compared with the surfaced-flow, the soil erosion rate showed stronger volatility in concentrated-flow, with the coefficient of variation of 71.49%~111.94%. 2) Mean flow velocity in concentrated-flow was significantly increased 28.15%~52.85% compared with surfaced-flow (p< 0.05), with increasing in flow rate. 3) Runoff conditions under both concentrated-flow and surfaced-flow were transitional flow and turbulent flow, while there was a significant difference in runoff state, which was rapid flow in concentrated-flow and tranquil flow in the surfaced-flow. 4) Soil erosion rate was positively correlated with the Reynolds number, resistance coefficient, shear stress, runoff power, and runoff unit energy under the two inflow patterns (p< 0.01). However, the optimal hydrodynamic indicators differed, with runoff power (R2= 0.68) for surfaced-flow and runoff shear (R2= 0.80) for concentrated-flow. 5) Compared with surfaced-flow, soil erodibility indexes Kτ, Kω and Kε in concentrated-flow increased by 166.67%, 81.25% and 113.86%, respectively, and the corresponding critical hydrodynamic thresholds (τ0, ω0, ε0) increased by 19.78%, 40.70%, and 42.11%, respectively. [Conclusion] The concentrated-flow shows stronger turbulence, has higher erosion energy, and triggers serious soil erosion. This study reveals the influence mechanism of inflow patterns on the slope erosion process and provides an important theoretical basis for the development of slope erosion prediction models under different inflow patterns for spoil heaps.