以西辽河红山水库修建后上游河道调整为例,说明了除来水来沙等的变化所引起的河流系统调整外,存在由于河流系统可调要素之间的相互联系、相互作用,在水库水位上升后造成的溯源淤积发展中,主、支流河道,上、下游河段冲淤相互影响,槽、滩淤积相互转换,地生态系统调整的影响下,产生的可调要素的复杂多向的调整过程。

This article deals with the processes and mechanisms of channel adjustments of the main stream and a tributary, the Yangchangzi River, upstream of Hongshan reservoir on the Laoha River, which is located in the northeast of China. The channel adjustments are reflected by changes of channel capacity, ratio of square root of channel width to depth, slope, bed material composition and channel pattern. It was illustrated that, in the processes of channel accretion headward caused by uplifted water level, the feedback couples between main stream and tributaries, between upper and lower reaches, between channel and floodplain and between ecosystem and river system were getting active. Under the influences of the complex feedback mechanisms, the channel capacity of the studied reach had undulated obviously in the general decrease tendency, the channel slope and the median grainsize of bed materials increased after strongly lowered, the geometry of channel was adjusted favorably to sediment transport in long term. The channel pattern of the studied reach has changed from wandering to sinuous under the influences of many factors. The adjustment of the channel of the tributary showed similar characteristics as that of the main channel. The sediment concentration of the tributary decreased after its erosion basis was raised.