吐鲁番地区水面蒸发演化特征及影响因素

Study on evolution characteristics and influencing factors of water surface evaporation in Turpan

【目的】对吐鲁番地区近50 a来的水面蒸发变化趋势、周期、突变及演化特征进行研究。【方法】利用小波分析、曼肯德尔检测法(M-K)及灰色关联法进行统计分析。【结果】1970~2020年吐鲁番地区水面蒸发经历了3个不同变化时期,1970~1990年为缓慢上升期,年均升高2.1 mm;1990~2015年为明显下降期,年均下降7.8 mm;2015~2020年为显著上升期,年均升高76.9 mm。1970~2020年蒸发呈现3个震荡周期,分别为3~5、10~15、25~30 a,其中28 a为主周期,包括低蒸发-高蒸发-低蒸发-高蒸发-低蒸发5个变化阶段。蒸发量在1991年发生突变,1991年后显著下降,2015年后有明显上升。在50a尺度上,影响蒸发的主导因素为日照时数和温度,10 a尺度上为温度和水汽压,5 a尺度上演变为温度和日照时数,其中降雨和相对湿度对蒸发的影响逐步上升。未来5 a吐鲁番地区水面蒸发整体呈下降趋势,年均蒸发为3073.42 mm。【结论】温度和日照时数是影响吐鲁番地区水面蒸发的主导因素。

【Objective】To reveal the variation trend,periodicity,sudden change and evolution characteristics of water surface evaporation in Turpan during last 50 years.【Method】Wavelet Analysis,Mankendall Detection(M-K)and Grey Correlation methods were used to analyze the data.【Result】From 1970 to 2020,the water surface evaporation in Turpan experienced three periods,including a slow rising period with an annual increase of 2.1 mm(1970~1990),a significant decline period with an average annual decline of 7.8 mm(1990~2015)and a significant increase period with an average annual increase of 76.9 mm(2015~2020).The evaporation showed three oscillation cycles in last 50 years,including 3~5 years cycle,10~15 years cycle and 25~30 years cycle,of which,28 years cycle was the main cycle with 5 variation phases(low evaporation,high evaporation,low evaporation,high evaporation and low evaporation).A sudden change of evaporation occurred in 1991,decreasing significantly after 1991,significantly increasing again after 2015.On 50-year time scale,the dominant factors affecting evaporation were sunshine hours and temperature;On 10-year time scale,they were replaced by temperature and vapor pressure;On 5-year time scale,they were temperature and sunshine hours.The influence of rainfall and relative humidity on evaporation gradually increased.5)The water surface evaporation in Turpan showed an overall downward trend in future 5 years,with an average annual evaporation of 3073.42 mm.【Conclusion】Temperature and sunshine hours were the dominant factors affecting water surface evaporation in Turpan.