【摘要】 利用近５００年我国旱涝等级历史资料及新中国４０多年气象资料，采用天气、气候及统计方法，计算了中线地区干旱指标，分析了华北地区和汉水上游水库库区干旱分布特征、各区区域性干旱遭遇及库区供水区与北方需水区旱涝变化的长期特征，供南水北调决策参考。更多还原

【Abstract】 By use of data 526 years, the methods of synoptics, climatology and statistics have been investigated for the characteristics of drought and flood that over North China and the Hanshui River valley, and the drought index computed also. The long-range evolvement of regional drought and flood distribution, and the requirement of water resources along the mid-line Water Transfer from South to North China were given.更多还原