广西右江历史洪水调查

Historical Flood Survey of Guangxi Youjiang River

每个工程设计,都要进行历史洪水调查,历史洪水调查要按准则去考证;不需要到坝址峡谷段人烟稀少处去查找洪痕,而是要到人口较为密集的水淹区去查访,查找洪痕。可靠的同一年洪痕水位,上下游应该一致,各河段的水面线应该是连续。流量估算由H^Q曲线查出(也可以用比降法推算)。历史洪水重现期,应把历史洪水灾情按大小顺序排队,进行分析和由老人年龄推测,该长则长,该短则短,不要加框框限制。现以我们调查的右江历史洪水实例来说明洪水调查的准则和方法。

Historical flood survey must be done based on some principles in design of each project. Flood marks shall be looked for in flooded region with dense population instead of valleys at dam site rarely inhabited. The flood mark level in a year is reliable only when that of the upstream is the same with that of the downstream, and the water surface profile of each river reach shall be in the same line. Flow estimation is derived from HQ curve （or by gradient method）. The recurrence interval of historical flood shall be reckoned in accordance with the scale of historical flood disaster and the age of the elderly. Principles and methods of historical flood survey are elaborated in this paper by taking the historical flood of the Youjiang River as an example.