黄河流域干旱频率分布及轮次数字特征分析

Analysis on Drought Frequency Distribution and Digital Characteristics of Number of Turns of the Yellow River Basin

从黄河流域干旱的研究现状以及方法论出发,利用游程分析理论,分析了1001—2000年黄河流域部分监测点每100 a的干旱年数,对1470—2000年黄河流域20个监测点的统计数据进行游程理论的数字特征计算,绘制了黄河流域各监测点的干旱重现期等值线图,利用K-means方法对监测点的数字特征进行了分类。结果表明:黄河流域各监测点的干旱年数呈总体上升趋势,1401—1700年,所有监测点的干旱年数不断增加,1701—1900年各监测点的干旱年数最低在每百年20次,20世纪至今干旱有增多趋势;产生重要影响的频繁干旱易发生于黄土高原、华北平原;长治、德州、太原、临汾、济南、西安等地区比其他地区在较长时间内更容易发生大旱,且连旱年数更长。

The paper analyzes the drought years of each 100-year of some monitoring sites in the Yellow River basin in the period of 1001-2000,calculates the numerical characteristics of runs theory of statistical data of 20 monitoring sites of the basin in the period of 1470-2000 and maps a contour map of drought return period of each monitoring site of the basin by using the theory of runs analysis and viewing from the research status and methodology of drought of the river basin.It classifies the numerical characteristics of monitoring sites by using K-means method.The outcomes show that a) the drought years of each monitoring site in the river basin shows an upward trend in general,the drought years of all the sites continuously increase in the period of 1401-1700,the minimum drought year of each site in the period of 1701-1900 is 20 times per 100-year and it is increasing from the 20th century up to now and;b) the frequent drought that has significant impact is easily happened in the Loess Plateau,the North China Plain,Changzhi,Dezhou,Taiyuan,Linfen,Jinan and Xi'an where a serious drought continuing for years is easily happened in a longer period comparing with the other regions.