河流泥沙交换运动是河流泥沙运动力学中主要难题之一,泥沙交换运动的过程与强度决定了河床冲淤的速率,从而引起河床冲淤演变。归纳总结了河床泥沙上扬通量推演过程及影响因素、河床泥沙粗细交换中泥沙扩散方程以及泥沙交换层厚度方程的形成过程、泥沙交换数学模型的建立、泥沙交换试验研究的方法等最新研究进展,同时梳理该方向研究存在的关键问题和未来趋势。目前尚未统一化的理论公式,计算方法均以经验公式为主,且缺乏可靠实测资料的充分验证。研究有助于深入了解河流近底泥沙交换研究的最新进展,为未来深入研究泥沙交换的重点方向提供参考。

Sediment exchange is one of the key issues in the evolution of riverbed erosion and deposition, and its study holds significant importance for river management and engineering practices. This study systematically reviews domestic and international research progress over the past three decades, focusing on the mechanisms of coarse and fine sediment exchange near the riverbed from four aspects: theoretical models, mathematical models, experimental methods, and field data analysis. The results demonstrate that existing theoretical models (e.g., upward flux formulas based on turbulent bursting, energy balance, and diffusion theories) largely depend on empirical assumptions, lack universally applicable mechanism descriptions, and face limitations due to insufficient field data validation. Although mathematical models describing three-state transitions among suspended load, bedload, and bed material have gradually incorporated probabilistic methods such as Markov chains, they still face challenges in accurately representing sediment exchange process under non-uniform flow conditions. Experimental studies reveal that medium-diameter sediments exhibit higher upward flux due to turbulent bursting and exposure effects. Moreover, formulas for exchange layer thickness dominated by sand wave migration require modifications to account for the influence of resistance transitions in sandy rivers. This study proposes three innovative future directions: (1) integrating prototype observation data to establish unified theoretical formulas for sediment exchange; (2) developing high-precision observation technologies to overcome the bottleneck in dynamically capturing random sediment collision processes; and (3) combining machine learning with physical models to build predictive systems for sediment state transitions. This review provides systematic references for advancing the understanding of sediment exchange mechanisms and optimizing engineering practices.