1981—2010年乌昌地区20cm蒸发皿蒸发量变化原因分析

Causes Related to Change of Evaporation from 20-cm Pans in the Urumqi-Changji Region during the Period of 1981-2010

选用1981—2010年乌昌(乌鲁木齐—昌吉)地区20 cm蒸发皿蒸发量资料,采用气候趋势法分析其变化趋势,结果表明:30 a间中、高山带蒸发量呈增加趋势,其中高山带增加较明显;平原区、低山带蒸发量以减小趋势为主,其中平原区减小速率最大。四季中大西沟和天池蒸发量均为增加趋势,其中春季和夏季增加较显著,平原区、低山带蒸发量四季均为减小趋势,其中夏季减小最快,其次为春季和秋季,冬季减小趋势较弱。用累积距平法做突变检验,乌昌地区在过去30 a高山带蒸发量在20世纪90年代末发生了快速增加;中、低山带蒸发量突变不明显,平原区大部分站蒸发量80年代末发生突变性减少现象。偏相关系数的显著性分析表明,高、中山带蒸发量增加的主导因子是气温升高;低山带蒸发量下降的主导因子是相对湿度增加;而平原区蒸发量减小的主导因子是风速减小。

The data of evaporation from 20-cm pans in the Urumqi-Changji region during the period of 1981-2010 were used to analyze the evaporation trend in the study area using climate trend method.The results revealed that,in recent 30 years,the evaporation was increased in mid-mountain and alpine zones,especially in alpine zone;it was in a decrease trend in plain and hill zones,especially in plain.Seasonally,the evaporation was increased in the Daxigou and Tianchi regions,especially in spring and summer;it was in a decrease trend in plain and hill zones,especially in summer,and then in spring,autumn and winter.Accumulative anomaly was used to test the sharp change of evaporation.The results showed that the evaporation in the Urumqi-Changji region was sharply increased in the alpine zone in the late 1990s,the sharp change of evaporation was not significant in mid-mountain and hill zones,and the evaporation was sharply decreased in most parts of plain in the late 1980s.The analyzed results of the coefficient of partial correlation revealed that the dominant factor affecting evaporation was the increase of temperature in the alpine and mid-mountain zones,the increase of relative humidity in the hill zone,and the decrease of wind speed in plain.