基于自然分区的1960—2018年中国气候变化特征

Trend of Climate Variation in China from 1960 to 2018 Based on Natural Regionalization

中国地域辽阔,气候变化存在明显的区域差异,从区域尺度对中国气候变化进行对比分析,对中国地表环境变化的归因研究具有重要意义。以1960—2018年中国483个气象站观测数据为基础,结合自然区划,分析了温度、降水、潜在蒸散和湿润指数的变化特征。结果发现,各气候要素变化具有明显的空间差异性。温度总体呈现显著上升趋势,平均增温速率为0.278℃/10a,但北方地区升温幅度大于南方地区,青藏高原大于同纬度的亚热带区域,温度年内变化总体呈现减小趋势,并通过0.05置信度检验。降水量在西北和东南地区呈现增多趋势,而在东北—西南向的生态过渡带附近区域有减小趋势,除亚热带湿润地区和热带湿润地区,其他生态区降水集中度都为明显减小趋势,降水年内变化相对均衡。在全国尺度上,潜在蒸散和湿润指数都呈现增大趋势,其中,湿润指数通过0.05置信度检验,但各生态区之间趋势差异明显。亚热带地区西部湿润指数减小趋势非常显著,而亚热带地区东部、西北干旱地区的西北部以及中温带地区的增大趋势非常显著。总体上,近59年来中国经历了一个以暖湿化为主要特征的气候变化过程,特别显著的是在西北干旱区、青藏高原区和中温带湿润/半湿润区。气候变化特征的研究将有助于解析地表环境和生态系统影响机制,预估未来气候变化风险,为区域气候变化应对和生态建设提供科学依据。

China has a vast territory,and there are obvious regional differences in climate change. The comparative analysis of China’s climate change on a regional scale is of great significance to the attribution study of China’s surface environmental change. Based on the observed data of 483 meteorological stations nationwide from 1960 to 2018,the trends of temperature,precipitation,potential evapotranspiration,and moisture index were analyzed in conjunction with natural regionalization. The results showed that the variations of climatic factors exhibited the obvious spatial heterogeneity. Temperature showed a significant rising trend,with the average warming rate of 0.278 ℃/10 a. Spatially,the increasing magnitude in the northern region was greater than that in the southern region,and the Tibetan Plateau region was larger than the subtropical region in the same latitude. The annual fluctuation of temperature showed a decreasing trend,and passed the 0.05 confidence test.Precipitation tended to increase in the northwest and southeast regions,while a decreasing trend was detected in the vicinity of the northeast-southwest ecological transition region. Except for subtropical humid region and tropical humid region,the annual fluctuation of precipitation in other ecological regions tended to remain constant. At the national scale,both the potential evapotranspiration and the wetness index showed an increasing trend,and wetness index passed the 0.05 confidence test. The significant decreasing trend of wetness index was found in the west of subtropical region,while the significant increasing trend was examined in the east of subtropical region, northwest of northwest arid region and mid-temperate region. Overall, China had experienced a dramatic climate change characterized by warming and wetting in recent 59 years,especially in northwest arid region,Tibetan Plateau region,and mid-temperate humid/semi-humid region. The study of the trend climate change in China is helpful for analyzing the impact mechanism of surface environment and ecosystem,and predicting the future climate change risk,which will provide scientific basis for regional climate change adaption and ecological construction.