【摘要】 本文从分析近年来我国部分地区发生的一些大暴雨和特大暴雨洪水资料入手,在纳希(J.E.Nash)瞬时单位线模式基础上,提出了一种由实测资料推求一次洪水中不同时段净雨强度条件下相应不同单位线分析方法.通过对25个小流域站176次洪水的分析计算,获得了天然小流域单位线滞时与净雨强度和单位线峰与量非线性关系的初步成果.文中指出各流域单位线对净雨强度的非线性反应,在其各自的临界雨强范围内都很明显,而超出其临界雨强以上不很明显或趋于线性;这个临界雨强大致在40～50毫米/小时之间;同时,本文还给出了淮河山区小流域非线性指数的初步综合成果.这些对解决单位线的推求、变化和外延问题可能有一定参考价值. 这种分析方法,仍属于经验性的近似分析方法,因而在此基础上所获得的某些看法尚受基本资料处理的精度、单位线线型等影响.更多还原

【Abstract】 By analyzing the records of some large storm floods and extraordinary ones taken place during recent years in several districts in China, this article sets forth a method based on Nash’s model of instantaneous unit hy-drograph. The proposed method can be applied to estimate different unit hydrographs relevant to different values of rainfall intensity respectively for different time interval in one flood process.Preliminary results of nonlinear relationship are obtained between the lag of an unit hydrograph and effective rainfall intensity, as well as between the peak and runoff volume of an unit hydrograph, through the analysis and calculation of 176 floods from 25 small catchments (F =41-1440 km2 ) . It is pointed out that the nonlinear response of the unit hydro-graphs to effective rainfall intensities, in the case if rainfall intensities are under some critical values about 40-50 mm per hour, is highly evident, but while beyond that limit, it becomes ambiguous or approaches to a linear relationship. Meanwhile, some preliminary synthetic results are obtained for nonlinear indices applied to the mountainous district of the Huai River. These may be of some reference value to the solution of the problems concerning the derivation, variation and extrapolation of unit hydrographs.The methodology here are still in the category of empirical approximated analysis, so that some views developed on this basis are influenced more or less by the accuracy of the elementary data-processing and the type of unit hydrograph.更多还原