汉江上游与黄河晋陕峡谷历史大洪水对比研究

Comparative study on historical heavy flood in the upper reaches of the Hanjiang river and the Shanxi-Shaanxi gorge of the Yellow River

对汉江上游与黄河中游晋陕峡谷公元1800a以来发生的大洪水事件进行统计与对比分析。结果表明:1)历史时期汉江上游大洪水发生频率高于晋陕峡谷。1920a以后,随着全球气候变暖,汉江上游和黄河中游大洪水都有发生频率增大、间隔年份缩短的趋势。2)受副高边缘到达时间差异的影响,汉江上游大洪水时间过程呈"M"型;晋陕峡谷大洪水时间过程呈"A"型。3)影响两地降水的环流形式相似,但水汽的主要来源有所不同。在汉江上游,水汽来源既有东南季风也有西南季风带来的暖湿气流;在黄河中游,东南季风带来的水汽是降水的主要来源。两地降水多少及大洪水的发生时间、强度与频次,受到东南季风、西南季风强弱及其组合情况的共同影响与控制。

The paper make statistics and comparative analysis on the heavy flood events in historical period from 1800AD in the upper reaches of the river Hanjiang and the Shanxi-Shaanxi Gorge of the Yellow River were conducted.The main conclusions are as follows：（1）The occurring frequency of heavy flood in the upper reaches of the river Hanjiang was higher than that in the Shanxi-Shaanxi Gorge of the Yellow River,but after 1920a,along with the global warming,it was increased obviously in two regions too;（2） By the influence of the time difference of the arriving of the edge of West Pacific Subtropical High（WPSH）,the time process of the historical heavy flood in the upper reaches of the river Hanjiang showed ＂M＂ type;and in the Shanxi-Shaanxi Gorge of the Yellow River,it was ＂A＂ type;（3） Circulation form that affected the precipitation of two places was similar,but the major source of steam was different.In the upper reaches of the river Hanjiang,the steam sources of precipitation were southeast monsoon and southwest monsoon;In the middle reaches of Yellow River,the southeast monsoon that brought water vapor was the main source of precipitation.In the two place,the precipitation,time,strength and frequency of big floods were commonly influenced and controled by the strenght of the southeast monsoon and southwest monsoon and their combination condition.