摘要
１９９８年长江发生了一次全流域性大洪水，中游干流河段普遍超过或接近有记录的历史最高水位。形成高洪水位的基本原因有洪水峰高量大、分洪溃口少、江湖槽蓄容量减小、江湖关系改变及水位流量关系的变化及河道冲淤等影响因素。对螺山站各种影响因素的定量分析得出，１９９８年螺山站出现创历史最高洪水位（较１９５４年最高洪水位高出１．７８ｍ）的主要原因是：①１９５４年受分洪、溃口影响同水位流量反常加大和１９９８年受壅水影响，同流量水位反常加高；②１９５４年后江湖槽蓄容量减少；③局部河段的河床冲淤变化。螺山河段水位流量关系受异常水力因素变化的影响极大，它向设计部门提出了在不同洪水典型之间，同流量有不同水位，是有待研究的新课题。
A basin wide severe flood occurred in the Yangtze valley in 1998, with flood stages along the main stem of middle Yangtze generally exceeding or approaching the recorded historical highest water levels. Main causes resulting in such higher stages are: large flood volume and high flood peak, less flood diversion and dyke breach, reduced regulation storage capacity of river channel and lakes, changed relationship between river and lake, variation of stage discharge relation, river bed scour, and river deposition etc.. Various factors affecting the stage at Luoshan Hydrologic station are analysed, and the result shows that main causes of occurrence of recorded historical highest flood stage 1.78 m higher than maximum flood stage occurring in 1954, at this station in 1998 are: ① in 1954, influenced by flood diversion and dyke breach, the flood discharge through the station was larger at the same stage; and in 1998, due to influence of backwater, the flood stage at the station was higher with the same discharge; ② since 1954, the regulation storage capacity of river channel and lakes has been reduced; ③ variations of scour or sedimentation have occurred in some river reaches. The stage discharge relation at Luoshan Hydrologic Station is greatly influenced by the changing hydraulic factors, and for floods different pattern, there are different stages corresponding to the same discharge, thus, it is a new question to be studied.
出处
《人民长江》
北大核心
1999年第2期29-31,共3页
Yangtze River
