中国1951—2018年气温和降水的时空演变特征研究

Study on the Spatiotemporal Evolution of Temperature and Precipitation in China from 1951 to 2018

利用1951—2018年中国699个气象站逐日的气温、降水数据,采用Mann-Kendall检验、小波分析、RClimDex极端气温指数方法,研究中国气温和降水时空演变特征。结果表明:在时间上,中国气温呈现明显的增加趋势,降水增加滞后且缓慢,气温和降水存在多周期变化特征,在大时间尺度上存在关联关系,以最高气温表达的冰冻日数ID0和暖昼日数TX90p较之以最低气温表达的霜冻日数FD0和暖夜日数TN90p变化幅度小,最长持续湿润日数和最长持续干旱日数呈下降趋势,气候变化以暖湿化为主要特征;在空间上,平均气温和降水量都表现出纬度方向上的降低趋势,等值线整体向北移动,很大程度上受地形影响,表现出相辅相成的空间分布特征,暖昼日数TX90p和夏季日数SU25在全国范围内均为正值,冰冻日数ID0和霜冻日数FD0存在大部分区域的减小,最长持续干旱日数与最长持续湿润日数在空间上的变化存在一定程度的相反趋势,极端降水事件存在增加趋势。研究气温和降水的时空演变特征是了解和应对气候变化对区域影响的重要内容。

This study used daily temperature and precipitation data from 699 weather stations in China from1951 to 2018 to study the spatiotemporal evolution characteristics of temperature and precipitation in China,by using Mann-Kendall test,wavelet analysis,and RClimDex extreme temperature index methods. The results show that:In terms of time,the temperature in China presents an obvious increasing trend;the increase in precipitation is lagging and slow;the temperature and precipitation have multi-period changes;and there is a correlation on a large time scale. With the number of freezing days ID0 expressed by the highest temperature and abnormal warmth compared with the number of frost days FD0 and the number of warm night days TN90 p expressed in the lowest temperature,the number of continuous days TX90 p has a smaller change. The longest continuous precipitation days CWD and the longest drought duration CDD show a downward trend. Climate change is mainly characterized by warming and humidification. Spatially, the average temperature and precipitation both show a decreasing trend in the latitude direction. The contours move northward as a whole,which is largely affected by the topography,showing complementary spatial distribution characteristics. The number of warm days TX90 p and the number of summer days SU25 are positive across the country. The number of freezing days ID0 and the number of frost days FD0 decrease in most areas. The longest continuous dry days CDD and the longest continuous humid days CWD have a certain degree of opposite spatial variation,and there is an increasing trend in extreme precipitation events. Studying the temporal and spatial evolution characteristics of temperature and precipitation is an important part of understanding and coping with the impact of climate change on the region.