近41年浙江衢州地区蒸发量变化特征及影响因素分析

Evaporation: Variation Characteristics and Influence Factors in Quzhou for Nearly 41 Years

基于衢州地区5个气象站1973—2013年逐月气象要素,采用线性趋势倾向估计、相关分析、Mann-Kendall非参数检验、多元回归分析等方法,分析了蒸发量的变化特征及影响因素。结果表明:衢州地区中东部年及四季蒸发量呈显著上升趋势,特别是近10年蒸发增多趋势明显,西部年及夏、冬季蒸发量呈显著下降趋势,年蒸发下降速率小于中东部上升速率。衢州地区夏季蒸发最大,冬季最小,蒸发量月际变化呈单峰型,最大月为7月,衢州地区中东部年及四季蒸发量均发生突变,而西部只在年、春、夏、冬季发生突变。年蒸发量与相对湿度、水汽压、降水量呈负相关,与平均最高气温、温度日较差呈正相关。相对湿度、水汽压减少,气温上升,温度日较差增大是衢州地区中东部蒸发量上升的主要因素。

This paper analyzed the variation characteristics and the impact factors of evaporation in Quzhou. Based on the monthly meteorological elements at 5 meteorological stations during 1973 to 2013, the authors adopted various analysis methods, including linear trend tendency estimation, correlation analysis, Mann- Kendall nonparametric test, and multiple regression analysis. The results showed that： the annual and seasonal evaporation presented a significant ascending trend in mid-east Quzhou, especially in the recent decade; the annual, summer and winter evaporation had a significant declining trend in west Quzhou; the declining rate of annual evaporation in west region was smaller than the ascending rate in the mid-east region; the seasonal evaporation was the highest in summer and lowest in winter; the monthly evaporation showed a single peak variation, and the peak value was in July; the mutation of the annual and seasonal evaporation occurred in mid- east Quzhou, while the mutation of the annual, spring, summer and winter evaporation occurred in the west region; the annual amount of evaporation had a negative relationship with the relative humidity, vapour pressure and the precipitation, while it had a positive relationship with the mean maximum air temperature, diurnal air temperature range. The main factors accounted for the ascending of evaporation in mid-east Quzhou were the reduction of relative humidity and the vapour pressure, the ascent of the mean air temperature and the increase of diurnal air temperature range.