Exploring the temporal and spatial variations of precipitation and drought is an important topic in hydro-logy. Based on the precipitation data of 619 meteorological stations in China from 1951 to 2018, we used anomaly percentage method and Morlet wavelet analysis to analyze the temporal and spatial variations of annual precipitation and drought. The results showed that annual precipitation in China showed a stepwise decreasing trend from southeast to northwest during the study period, and that the intensity of annual precipitation change was on the contrary. The precipitation near the boundary of the second and third steps showed a downward trend, and the abrupt change of precipitation occurred mainly in the 1960s and 1970s. The rest region was on the rise, with substantial changes in the 1990s. The main period of precipitation was short in the regions with temperate continental climate and temperate monsoon climate. From 1960s to 2010s, the area of arid land in China had decreased, while that of the semi-arid area and semi-humid area had increased gradually, especially in the recent decade. An aridity boundary was found between 30° N and 40° N, with drought frequency in its north being much more than the south. On the whole, the frequency and scope of drought events showed a decreasing trend and its interdecadal shift direction was from the central part of northwest China to the southern part of North China and then to the northern part of North China.
探求降水量及干旱时空变化特征及规律是当前水文学研究的重要课题。基于中国619个气象站1951—2018年的降水量数据,采用距平百分率法和Morlet小波分析等方法,揭示年降水量及干旱的时空变异。结果表明: 研究期间,中国年降水量空间上呈东南至西北阶梯递减的特征,多年降水量变化剧烈程度反之;地势二、三阶梯分界线左右区域降水量呈下降趋势,且多于20世纪60—70年代发生突变,其余地区呈上升趋势,大多数突变发生于20世纪90年代;温带大陆和温带季风气候区降水量主周期小。20世纪60年代至21世纪10年代,中国干旱区面积减少,半干旱区面积增加,特别是近10年干旱和半干旱区面积减小,半湿润区面积增大。在30°—40° N之间发现一条干旱南北差异分界线,分界线以北干旱次数远多于以南;干旱的主体区域在年代际的转移方向为西北中部→华北南部→华北北部,发生次数及分布范围逐渐减小。.
Keywords: China; drought; precipitation; temporal and spatial variability.