摘要
综合气象干旱指数(Ci指数)是以标准化降水指数、湿润度指数及近期降水量为基础,同时考虑了降水和潜在蒸散两项因子而设计的干旱指标。通过对衡阳市各区域1960—2012年逐日Ci指数统计,运用非参数Mann-Kendall检验(MK检验),分析了近53年来Ci指数的年代际、年及季节变化特点。结果表明:衡阳市干旱日、重旱日及特旱日出现频率分别为24.6%、3.1%和1.2%,其中有94.3%和77.4%年份出现了重、特旱日,进入21世纪以后,特旱日出现频率略有增大;Pd值在冬、夏季呈减少变化,而在春、秋季则有增大趋势,且在Pd值较高的季节,其倾向率增大(减小)更为明显;Pd值在8～9月达到高点,而Pz和Pt则在10～11月达到较高水平,9月份Pz、Pt偏低是由于8月降水较7月偏多所致。
The integrated meteorological drought index （Ci index）is a designed drought indicator based on standardization precipitation index, moist index and the recently precipitation, and at the same time, the two factors of precipitation and potential steam bulk have been considered. The paper analyzed the Ci index decadal, years and the season changes features of the recent 53 years through the daily Ci index statistics from the year of 1960-2012 of Hengyang regions,by using the nowparameter Mann-Kendall test（MK test）. The results indicates that the appearing frequency of the Hengyang drought day（Pd）, heavy drought day （Pz） and the special drought day （Pt）are respectively 24.6 ~, 3.1% and 1.2 %, which has the year of 94.3 % and 77.4 % appeared heavy and special drought day. After entering the 21^st century, the frequency of special drought day slightly increased. The Pd value is reduced in winter and summer while there is an increasing trend in spring and autumn. And in the high season of Pd value,the increase （decrease）rate is more visible. The Pd value reached the high point in August and September, which Pz and Pt reached a higher level in October and November. The Pz and Pt is low in September is dute to the more precipitation in August than in July.
出处
《衡阳师范学院学报》
2013年第3期97-102,共6页
Journal of Hengyang Normal University
基金
国家自然科学基金项目(41171075)
衡阳市科技局2009年社会发展科技支撑项目(2009ks18)
湖南省科技厅项目(2012FJ3019)
