河流网泥沙输移模型中的标度规律

Scaling Laws in A Dynamical Model for the Sediment Transport in River Network

为了模拟河流网的泥沙输运过程,根据水流携沙力受河道冲淤的反馈自调节机制,提出了枯水期河流网泥沙输移的动力学模型.考虑枯水期水沙动力学过程类似于固定流量和含沙量条件下的稳态,用该模型模拟预测了水流携沙系数(表征携沙力)和冲淤量沿河道分布的标度规律.结果表明,携沙系数随河段的递增满足负幂律分布;平均冲淤量随河段的递增满足指数规律分布.

To investigate sediment transport process in river network, a dynamical model in a lower-water season is proposed based on the self-adjustment mechanism that there exists a feedback between the sediment-carrying capacity of stream are no large fluctuations in stream process on the river network can be and the erosion or sedimentation occurred in the channel. Since there flow and sediment concentration simulated by the steady solution in a lower-water season, the real of the model. The dynamics of the model reveals that the distributions of sediment-carrying coefficient （indicating the sediment-carrying capacity） and the quantity of erosion-sedimentation along the channel in the downriver direction may be dominated by scaling laws. They demonstrate that the average quantity of erosion-sedimentation exponently depends on the river segments, and the sediment-carrying coefficient distributes in power law along the channel.