中国气候分区ET_(0)未来演变趋势预测及归因分析

Prediction and Attribution Analysis of Future Evolution of ET_(0)in Climatic Regions of China

潜在蒸散发(ET_(0))是反映流域水文-气象过程演变的一项关键指标,了解ET_(0)变化特征及其驱动要素的定量影响,对应对未来气候变化下的水循环变异具有重要意义。基于5种气候模拟预测集合数据,通过Peman-Monteith公式预测中国2030—2060年ET_(0)的时空变化趋势,并利用偏微分方法定量分析了驱动ET_(0)变化的各要素贡献。结果表明:在RCP4.5和RCP8.5情景下,未来中国5大气候分区ET_(0)都呈现增加趋势,增加速率分别为1.32 mm/a和1.96 mm/a,亚热带气候区ET_(0)增速最快,而高原山地气候区增速最小,5个气候区在RCP8.5情景下ET_(0)增速都比RCP4.5情景下大。年内4个季节ET_(0)都呈现增加趋势,在RCP4.5情景下秋季ET_(0)增速最快(0.56 mm/a),在RCP8.5情景下夏季ET_(0)增速最快(0.63 mm/a)。未来ET_(0)变化主要受日最高气温、日最低气温以及实际水汽压的影响,其中日最高气温是未来ET_(0)变化的主导气象要素,实际水汽压次之,在年内4个季节ET_(0)变化的驱动要素分析中也发现了类似规律。研究成果可为中国未来水资源优化配置和农业灌溉管理提供参考依据。

Potential evapotranspiration(ET_(0))is a critical element that impacts the water cycle of a river basin.Understanding the characteristics of future changes in ET_(0)and the quantitative impact of its driving factors is of great significance for coping with the variation of water cycle under future climate changes.Using the Peman-Monteith formula and ensemble data from five climate models,we estimated the temporal and spatial trends of China’s potential evapotranspiration from 2030 to 2060,and applied partial differential methods to quantify the contributions of various factors driving ET_(0)changes.The findings reveal that under the RCP4.5 and RCP8.5 scenarios,the ET_(0)of five major climate zones in China will exhibit an increasing trend in the future,with rates of increase reaching 1.32 mm/a and 1.96 mm/a,respectively.The fastest growth rate of ET_(0)is observed in the subtropical climate zone,while in the plateau mountain climate zone,the growth rate is the smallest.The growth rate of ET_(0)in the five climate zones under the RCP8.5 scenario is greater than that under the RCP4.5 scenario.Overall,ET_(0)exhibits an increasing trend in all four seasons of the year.Under the RCP4.5 scenario,the ET_(0)growth rate is the greatest in autumn(0.56 mm/a),while under the RCP8.5 scenario,the largest growth rate is observed in summer(0.63 mm/a).Future changes in ET_(0)are primarily affected by daily maximum and minimum temperatures,as well as actual water vapor pressure.Daily maximum temperature is the dominant meteorological element governing the magnitude of ET_(0)changes,followed by actual water vapor pressure.Similar patterns were found in the analysis of the driving factors of ET_(0)changes in all four seasons.The research findiugs provide reference for optimal allocation of water resources and agricultural irragation management in future.