【摘要】 首先运用《中国近五百年旱涝分布图集》中的降水分级表达式,将河南省安阳地区1470～2000年的降水等级完善到2008年,然后根据游程分布理论,选择正常年份降水等级为截取水平,定义降水等级大于正常年份的为正游程,小于为负游程,讨论正负游程分布规律。最后,分析大旱(等级为5)和旱(等级为4)年持续时间的分布情况,得出不同等级游程分布规律,用于风险性决策。更多还原

【Abstract】 By using the expression of precipitation grade in Atlas of the Distribution of Droughts and Floods in China over the Past Five Hundred Years,ranked precipitation data from 2000 to 2008 was completed.Then according to run-length distribution theory,selecting normal year of precipitation as the interception grade level,the precipitation levels which greater than the normal year was defined as the positive run-length,which less than the negative run-length.The positive and negative run-length distribution was discussed.And then the severe drought(grade 5),drought(grade 4)years duration was analyzed to obtain the distribution of run-length at different grades distribution,which could be used for risk decision-making.更多还原