利用近30年的实际观测资料,分析贺州地区年平均气温和干旱指数的变化特征,结果表明:(1)贺州地区年平均气温有增高趋势,冬季和春季较大幅度变暖,带来“暖冬”,夏季反而稍微降温,出现“凉夏”,秋季稍有增温,但不明显;(2)贺州地区的年平均气温存在11a和4a左右的两个振荡周期;(3)在上世纪80年代初,贺州地区干旱指数有一次明显的年代际变化,由负值转为正值,干旱有加重的趋势,未来几年贺州地区干旱指数仍处于增强的趋势中,这与11~13a左右的振荡周期处于正位相有关。贺州地区4个站的干旱指数都有一个11~13a左右的振荡周期和一个2~6a左右的振荡周期。
By using real observational data from four weather stations (Zhaoping, Fuchuang, Zhongshan and Hezhou) in last three decades, changes of the mean annual temperature and drought index are analyzed. The result indicates that: firstly, mean annual temperature of the four stations shows obvious and large inter-annual change. Under the global climatologic warming circumstance, mean annual temperature shows an upward trend in Hezhou. For decadal time scale, the 1990's was obviously hotter than the 1980's, as well as the average level over the thirty years. Thus, the region is becoming hotter: winter and spring temperature will increase a lot leading to warm winters; reversely summer temperature will decrease only a little to cool summer. Autumn temperature will have a small increase. Secondly, mean annual temperature in Hezhou had periodic oscillations with 1 lyear and 4- year cycles. Thirdly, there were not extreme drought and humidity in the last 30 years in Hezhou, despite drought index showing obvious inter-annual changes. The drought index had a distinct inter-decadal change in early 1980's, changing from negative value to positive value, which indicates that the drought will become more serious. The drought index increase in the few years may be correlated with 11-13-year periodic oscillations positively. Last, all the four stations show approximately periodic oscillations with 11-13 years and 2-6 years.