1960年～2012年长江下游流域气候变化特征分析

Characteristics of Extreme Climate in Downstream Catchment of Yangtze River during 1960-2012

利用1960年~2012年长江下游地区34个气象站逐日资料,采用线性回归、bootstrap、Mann-Kendall检验、样条插值等方法,分析长江下游地区的极端气温和极端降水的变化特征。结果表明,1987年后极端低温日数开始减少,极端高温日数开始增加,且极端高温和极端低温都呈现显著上升趋势,极端低温的上升趋势更为明显;长江下游极端降水频次和强度存在明显的年代际差异,2000年以后极端降水频次有所减少但强度并未减弱。城市化对于城市降雨量的影响呈现出逐年变大的趋势,也使得城市周边地区的降水也出现一定的增大趋势。

The daily temperature and precipitation data of 34 meteorological stations during 1960 -2012 in downstream catchment of Yangtze River are based to analyze the characteristics of extreme temperature and precipitation in downstream catchment of Yangtze River by using linear regression, bootstrap, Mann-Kendall test and spline interpolation method. The results show that： （a） the extreme low temperature days began to decrease and the extreme high temperature days began to increase after 1987, the extreme high temperature and extreme low temperature also has a significant upward trend and the extreme low temperature trend is more obvious; （b） the frequency and intensity of extreme precipitation has significant diffidence between decades, the frequency of extreme precipitation after 2000 has decreased bat the intensity has not weakened; and （e） the impact of urbanization on urban rainfall is increasing year by year, and the precipitation in surrounding areas of city is also increasing.