近50年黄河中游三花区间降水特征分析

Analysis of Rainfall Character for Sanhua Interval in the Middle Reach of the Yellow River Nearly 50 Years

利用黄河中游三花区间（三门峡到花园口）近50a（1955—2004年）气候资料，分析了三花区间降水量的时空分布特征，结果表明：区间汛期降水量的年代变化趋势与非汛期大多相反；不论区间还是分区，20世纪90年代降水量较常年偏少都十分显著。近期（1986-2004年）年降水量较常年偏少1成左右。其中，汛期降水量偏少1～2成；非汛期区间和伊洛河偏少，沁河和干流为正常或略偏多。

The temporal and spatial distribution character of rainfall has been analyzed based on the climate data collected from 1955 to 2004 in the area between Sanmenxia and Huayuankou in the middle reach of the yellow river. According to the analysis, the annual rainfall change in flood seasons mostly manifests a trend contrary to that in the rest part of year; the rainfall in the 1990s was markedly less than usual both in the Sanhua interval and in the separate areas. The annual rainfall in the recent years （from 1986 to 2004） decreased by about 10% as compared to other years, with the rainfall in flood season decreasing by 10% to 20% ; the rainfall in the Sanhua interval and Yiluo river was less and that in Qin river and the main stream was as usual or more than usual.