陕南地区近47年来气温、降水变化特征分析

利用陕南地区7个气象站1961～2007年的气温和降水记录,运用线性趋势、距平分析、5年滑动平均,Morlet小波分析等方法,研究了陕南地区近47年来的气候变化特征。结果表明:近47年来,陕南地区气温呈波动上升趋势,其增长率为0.14℃/10a。春、秋、冬季气温在增加,并且冬季增暖最为明显,夏季气温略有降低。气温变化有明显的周期性,普遍存在着20a和3～5a的周期振荡信号;降水量呈减少趋势,平均每10a减少2.9mm。降水量的年际变幅表现为夏季>秋季>春季>冬季,春季和秋季降水减少,夏季和冬季降水增加,减少量大于增加量,导致春旱、秋旱加剧。Morlet小波分析表明降水在20a和4～9a的尺度上也有较强的周期振荡。

Temperature and precipitation change characteristics in south region of Shaanxi Province in recent 47 years

Using the temperature and precipition records from 1961 to 2007 of seven meteorological stations in south region of Shaanxi Province and with methods of linear trend,distance average analysis and five-year moving average,etc,we attempted to research the climate change characteristics in south Shaanxi Province region.The research results revealed that in the last 47 years,the temperature of this region showed witnessed wavelike rising tendency,with its rising rate of 0.14℃/10a.The temperature of spring,autumn and especially winter have shown increase,while summer has experienced a decrease in temperature.The temperature change also showed a clear periodicity,and periodic oscillation signal of 20a and 3~5a universally existed;as for precipitation,it showed a tendency of decrease,with a reduction of 2.9 mm per 10 a.The annual amplitude of precipitation showed: summer>autumn>spring>winter.The precipition of spring and autumn reduced,while that of summer and winter increased.Since the reduction was much bigger than the increase,spring and autumn drought have become severer.Morlet wavelet analysis showed precipitation also showed a comparatively stronger periodic oscillation on the scale of 20a and 4~9a.