黄河下游河床演变数学模型和初步研究及其应用

以黄河下游河床演变特性为基础，提出了漫滩水沙运动及水沙交换的处理方法，探讨了冲淤量沿河宽分布的准二维计算方法，分析了河床横向变化及其对纵向输沙的影响，并提出了相应的模拟方法，在已用实测资料对这几项研究率定的基础上，建立了适用于黄河下游的准二维数学模型，并用黄河１９６９－１９７８年实测资料进行了验算，验证成果表明，计算与实测基本一致，最后计算和比较了不同来水来沙方案对下游的影响。

Mathematical modeling of fluvial process in the lower Yellow River

Based on the investigations carried out by the authors a 1- D mathematical model of fluvial process in alluvial rivers has been istablished. The model has concentrated on simulating some characteristics of fluvial process in the lower reach of , the Yellow River. Three patterns of interchange of sediment between the main channel and the flood plains were suggested through analysing the plain geometry of the alluvial rivers. The relation of sediment concentration between the main channel and the flood plains can be derived from Eq. (l) The sediment diffusion equation taking account of the effects of flood plain aggradation on sedment transport in the main channel was cxplained by Eq. (2). The modified flow continuity eqation and momentum eqation concerning the different flow distances in the main channel and the flood plains were presented as Eqs. (3) and (4). The lateral channel bed changes including the shifting of the main channel and the channel bank failure have been concerned with Eq. (16) and (17) in the model. The changes of langitudinal channel also have been dealt with according to the vertical distribution of the velocity and the sediment conccrntration given by Eqs. (8) and (14). Thus the 1-D model has been verified by the long-term field data of the Lower Yellow River and good agreements have been obtained. The trends of the river changes with different plans were estimated and discussed using the model.