中文摘要：

为了深入认识南昌参考作物蒸散量（ET0）的时间变化特征,采用FAO推荐的Penman-Monteith公式计算南昌1961—2015年逐日ET0,并用Mann-Kendall趋势检验和突变检验法分析南昌ET0时间变化特征和突变时间,在此基础上使用通径分析法研究ET0变化成因。结果表明,南昌ET0年内呈现单峰曲线,7-8月最高,约占全年30%。从年际变化看,ET0和日照时数（n）无明显趋势,仅在8月呈现显著下降趋势,而相对湿度（RH）和风速（u2）显著下降,最高气温（Tmax）和最低气温（T_（min））显著上升。n和ET0多年累积距平曲线和月值曲线形状最接近,突变时间也最接近,分别在1990和1992年。n、u2、RH和T_（min）通径系数分别为0.513、0.466、-0.425和0.196,表明n最敏感,其后依次是u2、RH和T_（min）。n通过RH对ET0影响也较强（间接通径系数0.236）,高于T_（min）的直接作用。

英文摘要：

Penman-Monteith formula recommended by FAO was used to calculate the daily ET0 from 1961 to 2015. Mann- Kendall trend test and mutation test analysis were applied to study the ET0 variation characteristics and mutation of time of Nanchang, and path analysis was used to research the causes of ET0 variation. The result shows that Nanchang ET0 monthly presented single-peak curve ,with July - August being highest ,which accounts for ＇about 30% of the year. From the annual variation, ET0 and sunshine duration has no significant trend, only presenting a significant decline in August. There was a significant reduction in the relative humidity and wind speed, while the highest and lowest temperature rises significantly. Sunshine duration and ETa yearly accumulative anomaly curve had the closest curve shape, mutations in time was also the closest,which were in 1990 and 1992 ,respectively. Path coefficient of sunshine duration ,wind speed, relative humidity and lowest temperature was 0. 513,0. 466, - 0. 425 and 0. 196, respectively, which shows that sunshine duration was the most sensitive factor, followed by wind speed, relative humidity and the lowest temperature. The effect of sunshine duration through relative humidity on ETo was also strong（ the indirect path coefficients was 0. 236）, which was higher than the low- est temperature of direct action.