吉林省参考作物蒸散演变特征及气候成因定量分析

Evolution Characteristics of Reference Crop Evapotranspiration and Quantitative Analysis of Climate Causes in Jilin Province

参考作物蒸散是能量平衡和水分循环的重要环节,明晰吉林省参考作物蒸散演变特征及成因,有助于理解气候变化对水文循环的影响和科学开展灌溉。根据吉林省28个气象站1970-2019年的逐日气象数据,利用Penman-Monteith法、去趋势法探究考蒸散演变特征及其定量化成因。结果表明:近50 a中,吉林省年平均参考作物蒸散呈不显著的增加趋势,四季中,夏季蒸散减少,其他季节蒸散不同程度增加。近50 a中,吉林省各气象因子变化差距明显,年、季平均气温和水汽压差增加,风速和日照时数减少,其中风速和水汽压差的变化幅度明显大于气温和日照时数;吉林省年均蒸散变化由水汽压差和风速主导,各因子正贡献略超过负贡献,使年均蒸散呈弱增加趋势。春季平均蒸散演变主要由水汽压差和风速驱动,夏季平均蒸散由水汽压差、风速和日照时数共同驱动,秋、冬季平均蒸散演变是由水汽压差和风速驱动。空间上,西部地区年蒸散的变化主要由风速驱动,中部年均蒸散同时受到风速和水汽压差变化影响,东部由水汽压差变化驱动。吉林省西部春季蒸散变化主要由风速驱动,中部和东部春季蒸散由水汽压差主导;西部和中部地区夏季平均蒸散由日照时数主导,东部则主要由水汽压差驱动;西部和中部秋、冬季蒸散变化主要受风速影响,东部主要由水汽压差的变化驱动。

Reference crop evapotranspiration is an important part of energy balance and water cycle.Clarifying the evolution characteristics and causes of reference crop evapotranspiration in Jilin Province is helpful to understand the impact of climate change on hydrological cycle and scientific irrigation.Based on daily meteorological data from 28 meteorological stations in Jilin Province from 1970 to 2019,Penman-Monteith method and detrend analysis method were used to explore the characteristics of evapotranspiration and quantify the driving effects of meteorological factors on its annual and seasonal variations.The results showed that:In the past 50 years,the annual average reference crop evapotranspiration in Jilin Province showed an insignificant increasing trend.In the four seasons,the evapotranspiration decreased in summer,and increased in other seasons.In the past 50 years,the difference of meteorological factors in Jilin Province was obvious.The annual and seasonal average temperature and water vapor pressure difference increased,and the wind speed and sunshine hours decreased.The variation of wind speed and water vapor pressure difference was significantly greater than that of temperature and sunshine hours.The annual average evapotranspiration change in Jilin Province was dominated by water vapor pressure difference and wind speed,and the positive contribution of each factor slightly exceeded the negative contribution,which made the annual average evapotranspiration show a weak increase trend.The evolution of average evapotranspiration in spring was mainly driven by water vapor pressure difference and wind speed.The average evapotranspiration in summer was driven by water vapor pressure difference,wind speed and sunshine hours.The evolution of average evapotranspiration in autumn and winter was driven by water vapor pressure difference and wind speed.Spatially,the change of annual evapotranspiration in the western region was mainly driven by wind speed,while the central and eastern regions were driven by the change of water vapor pressure difference.The change of spring evapotranspiration in western Jilin Province was mainly driven by the negative contribution of wind speed decrease,while the spring evapotranspiration in central and eastern Jilin Province was dominated by the positive contribution of water vapor pressure difference increase.The summer average evapotranspiration in the western and central regions was mainly driven by the negative contribution of sunshine hours,while the eastern region was mainly driven by the positive contribution of water vapor pressure difference.The variation of evapotranspiration in autumn and winter in the western and central regions was mainly affected by wind speed,while the eastern region was mainly driven by the change of water vapor pressure difference.