水库下游河流再造床过程的时空演替现象——以丹江口建库后汉江中下游为例

在实测资料和前人研究的基础上,引入“空代时”假说,分析研究了丹江口建库后汉江下游河流再造床过程的时空演替现象。分析表明,河流再造床过程在冲刷延展、河床粗化、含沙量及其特征、岸滩侵蚀以及河型变化等方面具有较典型的时空演替现象。产生时空演替现象的根源在于河流自调整作用在同一变源下空间和时间响应的一致性,是过程的相似。输入水沙条件的变化、水库下游河道支流入汇、河床边界条件的变化以及因此导致的不同调整方式是引起时空演替复杂响应的主要原因。如能排除干扰、建立时空演替现象的数学模式将有助于水库下游河流调整的分析和预测。

Phenomena of replacement between spatial and temporal processes during the process of reformation downstream reservoirs:A case study of middle-lower Han river after the construction of Danjiangkou reservoir

Based on the observed data and the former research,the ergodic hypothesis is introduced to analyze the process of the reformation in the middle-lower Han river after the construction of Danjiangkou reservoir.It is concluded that the phenomena of replacement of spatial and temporal process is typical in the erosion development,the coarsen of riverbeds,the sediment concentration and the change of river regime,etc.The phenomena originate from the same response to the same generation in the self-organized process of rivers in the process.Change of flow and sediment conditions,inflow of branches,the different river boundary conditions and the different respond methods caused by the different of river boundary conditions are the cause of complex response in replacement of the spatial and temporal process.The proper numerical method of replacement of spatial and temporal may be useful to the rivers downstream of many reservoirs.