1960―2013年艾比湖绿洲湿地潜在蒸散量及地表湿润度变化特征分析

Analysis on the variation characteristics of potential evapotranspiration and surface moisture in the Ebinur Lake Oasis Wetland from 1960 to 2013

基于阿拉山口、精河、博乐、温泉4个气象站点1960-2013年地面观测气象数据,采用Penman-Monteith公式、Mann-Kendall检验、小波分析、主成分相关分析等方法分析艾比湖绿洲湿地年及季节潜在蒸散量及地表湿润度的特征变化及定量化成因,以期为艾比湖绿洲湿地区域的水资源科学配置提供科学依据。结果表明:(1)1960-2013年,艾比湖绿洲湿地年平均潜在蒸散量为1 063.52mm,夏季值最大为552.3mm,冬季最小为25.3mm,年平均潜在蒸散量以12.68mm·(10a)^-1的速率递减,各季节潜在蒸散变化趋势与年变化一致,夏季表现最明显;(2)Mann-Kendall检验表明,年均和春、夏、秋潜在蒸散量显著性突变时间分别是1991年、1994年、1994年和1993年,冬季不存在突变,显著性突变均发生在21世纪90年代,地表湿润度年突变时间为1985年;(3)艾比湖绿洲湿地潜在蒸散量及地表湿润度存在明显的周期变化,主震荡周期分别为29a和21a,以多、少交替发生,具有全域性;(4)风速是年及季节潜在蒸散量的主导因素,地表湿润度变化的主导因素是降水量和相对湿度。

Based on the monthly meteorological data of Alataw Mountain Pass,Jinghe,Bole and Wenquan station,the quantitative research and temporal characteristics of evapotranspiration and humidity index in Ebinur were calculated by using mathematical statistics of Mann-Kendall test,wavelet analysis,and the key climatic factors of influencing potential evaportranspiration and humidity were obtained by principal component analysis based on the meteorological factors. The results indicate that:(1)the annual mean evapotranspiration of the Ebinur Lake Oasis Wetland was 1 063.52 mm with a rate of -12.68 mm·(10 a)^-1 from1960 to2013 and the maximum amount of evapotranspiration was 552.3 mm in summer,which had the largest contribution to the annual total evapotranspiration,and the minimum amount of evapotranspiration appeared in winter. The seasonal variation of potential evapotranspiration was consistent with the annual variation,especially in summer.(2)The results of Mann-Kendall test show that mutation of annual evapotranspiration is 1991,and the mutation of seasons respectively appeared in 1993 in spring,1994 in summer and 1993 in autumn,then without mutation in winter.The significant mutations occurred in the 1990 s,and the mutation of land surface humidity occurred in 1985.(3)The results show that there were four types of time scales from 1960 to 2013:the main cycle is 29 a,and the cycles occurred more or less alternately with globality.(4)In summary,wind speed was the dominant factor of influencing potential evapotranspiration. The dominant factors that influenced the land surface humidity index were precipitation and relative humidity. Therefore,it is showed that the climate of Ebinur Oasis Wetland was generally getting warm and wet. According to the results,it is beneficial to provide scientific basis for the allocation of water resources in the Ebinur Lake Oasis.