近54年柳州干旱的时空特征分析-气象研究与应用

文章信息/Info

Title:: The spatio-temporal characteristics analysis of drought in Liuzhou nearly 54 years

Author(s):: Zhang Ling-yun¹; Li Yi-shuang¹; Yuan Ma-qiang¹; Zhang Xin²; 1. Liuzhou Municipal Meteorological Service, Liuzhou Guangxi 545001;
2. Luzhai County Meteorological Service, Luzhai Guangxi 545200

Keywords:: percentage of precipitation anomalies; correlation index; interdecadal variation

摘要:: 基于1961-2014年逐日降水资料,用降水量距平百分率作为划分干旱的指标,对柳州各季节干旱的时空特征进行了分析,结果为:(1)春季柳州干旱频数的空间分布特征是北部和东部多、其他地区少,夏季西多东少,秋季东北部最多、其他地区接近,冬季西南部多、东北部少、其他地区居中。柳州北部的干旱事件以轻旱、中旱为主,重旱、特旱事件主要发生在在中部和南部地区。(2)从春季到冬季,柳州的干旱发生严重程度有随时间递增的趋势,全市性的中旱、重旱、特旱事件主要发生在秋季和冬季,春季、夏季干旱事件全部为轻旱。(3)近54年柳州全市性干旱总频数的年代际变化呈单峰型,1980年代为波峰,1960年代和2010年代波谷。各季节干旱频数的年代际变化趋势是:春季和秋季1980年代以前干旱发生较多,1990年代以后干旱发生较少,夏季和冬季1980年代以前干旱发生较少,1990年代以后干旱发生较多。

Abstract:: Based on the daily precipitation data from 1961 to 2014, the spatio-temporal characteristics analysis of drought of each season in Liuzhou were analyzed by using precipitation anomaly percentage as a division of drought index. The results show that (1) In spring, the frequency of spatial distribution feature of drought is higher in north and east, but lower in other areas, in summer which is higher in west and lower in east, and when in fall, the highest is in the southwest and that of other places are very nearly the same, while in winter, it is higher in southwest and lower in northeast, then is median in other regions. Furthermore, the drought events of northern Liuzhou are mainly light drought and medium drought, while severe drought and extreme server drought mainly occur in the central and southern regions. (2) From spring to winter, drought severity increases with time, with medium, severe and extreme severe drought mainly in autumn and winter but light drought in the other seasons. (3) the decadal variability of the total frequency of drought of Liuzhou during recent 54 years show unimodal type with reaching peak in the 1980 s and decline to trough in 1960 s and 2010 s. The decadal variability of the seasonal drought frequency trend is:before 1980 s in the spring and autumn drought occurred more, but less after the 1990 s, before 1980 s in the summer and winter drought occurred less, but more after 1990 s.