新疆艾比湖绿洲潜在蒸散量年代际变化特征

潜在蒸散量在研究气候变化、监测农业旱情、提高农业水资源利用率等方面得到广泛应用。为研究新疆艾比湖绿洲潜在蒸散量年代际变化特征,该文使用1960—2013年艾比湖绿洲地区4个气象站点的数据,通过Penman-Monteith公式计算年和季节潜在蒸散量,利用Cramer突变检验分析和相关性分析与贡献率计算其特征变化。结果表明:1)20世纪90年代的潜在蒸散量在研究时间尺度中达到最低,自2000年后开始增加。春季、夏季、秋季的潜在蒸散量与年潜在蒸散量变化趋势一致,冬季无明显变化;2)通过Cramer法检验表明,春、夏、秋潜在蒸散量3季突变时间分别为1999年、1996年、1999年,冬季不存在突变,总体而言,潜在蒸散量突变均出现在20世纪90年代;3)风速是全年及季节潜在蒸散量的主导因素。研究可为艾比湖绿洲区域的水资源科学配置、农业灌溉管理以及脆弱生态环境恢复提供依据。

Decadal variation of potential evapotranspiration in Ebinur Lake oasis of Xinjiang

Evapotranspiration is one of the important parameters in hydrological and meteorological studies.Under the background of global warming,it is essential to accurately estimate the potential evapotranspiration (ET0) in arid and semiarid areas where the water resources are limited and excessively explored.In this study,we used the data of main daily meteorological factors such as temperature,relative humidity,wind speed and sunshine duration from 4 meteorological stations to calculate the ET0 based on Permen-Monteith equation for analyzing the spatial distribution and temporal change in the ET0 in Xinjiang Ebinur Lake oasis during 1961-2013.The Cramer mutation analysis was used for determination of the mutation point of ET0,the partial correlation analysis was conducted,and the contribution of the main climatic factors to ET0 was calculated.The results showed that:1) the accumulative anomaly of ET0 was positive in 1960-1989 and negative in 1990-1999.The ET0was the lowest in the 1990s and then increased since 2000.As a whole,the ET0 in the study area decreased from 1960 to 2013.The change of ET0 in the spring,summer and autumn was consistent with that of the whole year,and the change of ET0 in the winter was not obvious.The average ET0calculated based on the whole year from 1960-2013 was 1 064 rm.The ET0 in the spring,summer,autumn and winter accounted for 29％,52％,16％ and 3％ of the total,respectively,indicating that ET0 in the spring and summer had the largest contribution to ET0;2) the ET0 mutation was in the year of 1997 based on the whole year data,in 1999 based on the spring data,in 1996 in the summer and in 1999 in the autumn.ET0 was decreased at a rate of-2.81 mm/a from 1960 to 1996 and then increased at a rate of 3.43 mm/a since 1997 to 2013.There was no mutation in the winter;3) the mean temperature,daily range of temperature,sunshine duration,wind speed,relative humidity and annual precipitation had different influence on the ET0.In the spring of 1960-1998,there was a high correlation between ET0 and wind speed and relative humidity.In the spring of 1999-2013,ET0 had a high correlation with mean temperature,wind speed and sunshine duration.In the summer of 1960-1995 and 1996-2013,ET0 had a high correlation with the mean temperature,relative humidity,wind speed and sunshine duration.In the autumn of 1960 to 1998,ET0 had a high correlation with the mean temperature,relative humidity and wind speed.However,after 1998,ET0 only had a high correlation with wind speed.There was a high correlation between ET0 and mean temperature,relative humidity and wind speed in the winter.According to the relative contribution of each factor to ET0,the wind speed was the main factor affecting ET0 in the study area.In the spring,ET0 was also affected by the daily range of temperature,and in the summer,autumn and winter it was also affected by the mean temperature.The results would provide valuable information for restoration of fragile ecological environment water resources allocation,agricultural irrigation and management science.