六安地区近50年来降水量的变化特征

Analysis of Characteristics of Precipitation Changes in Liu'an of Anhui Province Over Last 50 Years

采用寿县、六安和霍山1956—2005年的降水量资料，运用离差系数、变化趋势、突变分析和功率谱分析等方法分析了六安地区50a来降水量的变化特征，初步探讨降水变化对农业生产的影响。结果表明：三站近50a来的降水量均呈正态分布，变异等级为中级；年降水量均随时间进程呈减少趋势，且减少速率顺序为六安〉寿县〉霍山；通过诊断发现三站50a来年降水量的变化过程均可以分为偏干、偏湿、干湿交替3个阶段，寿县和六安站的降水突变点在1992年，霍山在1965年；通过功率谱分析发现，寿县、六安和霍山站的年降水量分别有7～8a、2～3a和2a的明显周期性变化规律。

Based on precipitation data from 1956 to 2005 in Shouxian, Liu＇an and Huoshan County of Liu＇an region in Anhui Province, the characteristics of precipitation change was analyzed by using coefficient of variation （Cv）, changing trend, mutation analysis and power spectral analysis. The influence of precipitation changes upon agricultural production was analyzed. The results showed that the precipitation decreased in Shouxian, Liu＇an and Huoshan over last 50 years with an intermediate variation. The process of precipitation changes experienced three phases, namely partial dry, partial wet and dry and wet alternation. The Abrupt precipitation change in Shouxian and Liu＇an County appeared in 1992, while it was in Huoshan County in 1965. The spectral analysis showed that the periodicities of precipitation were seven to eight years, two to three years and two years in Shouxian, Liu＇an and Huoshan respectively.