黎河河道演变的数学模型——天然河道用作输水通道后的演变

天然条件下的山前性河流黎河被用作引滦入津的输水河道，来水条件的巨变和大量工程引起的河床调整，为研究这一调整我们建立了具有如下特点的数学模型：1、考虑了自上而下床沙粒径的巨大变化；2、反映了卵石夹沙河床宽级配的输沙特点以及清水冲刷时的粗化过程；3、模拟了粘性土河床的冲刷特性；4、考虑了跌水坎的不规则断面宽顶堰的过流特点以及有工程措施和人为干扰下的河床演变特点。本文介绍了上述数学模型的主要内容，这对于其它跨流域引水工程和河道治理工程有参考价值。

A Mathematical model of fluvial processes of the Lihe River fluvial processes caused by conveying water along a natural river

The Lihe River, a seasonally intermittent river under natural conditions, is used as a conveying canal for diverting water from the Luanhe River to Tianjin. Dramatic changes of oncoming flow conditions and sets of engineering structures cause a significant adjustment of the river. In order to study fluvial processes of the Lihe River, a mathematical model has been developed. The model is characterized by following features: 1. The significant change of bed material along the river course is taken into consideration; 2. Features of sediment transport on gravel sand bed with wide range of grain sizes are reflected, and the armoring processes during bed erosion by clear water is simulated; 3. The erosion of cohesive bed is simulated; 4. Features of flow over non uniform broad crest weir are considered while describing flow over step dams, and fluvial processes of river with engineering structures and artificial interference are simulated. Such a mathematical model described in this paper can be referred by other interbasin diversion works.