环县近60年蒸发量变化特征及影响因子分析

Variation Characteristics and Influence Factors Analysis of Evaporation in Huan County in Recent 60 Years

为了研究陆面水分循环特征以及干旱致灾过程和机理,利用甘肃环县1958—2014年的气象资料,分析环县57年来蒸发量的季节和年际变化趋势、阶段性突变特征及影响因子。结果表明:蒸发量具有明显的年际变化特征,年及四季最大蒸发量均出现在20世纪50年代后期,最小蒸发量出现在2000年后。通过相关分析发现,蒸发皿蒸发量与平均风速、平均气温和日照时数具有极显著的正相关,与相对湿度、降水量具有较显著的负相关。分析发现环县蒸发量出现减少趋势的原因主要是风速减小,其次是日照时数的减少和降水量的增加。

In order to study the land water cycle characteristics and drought disaster process and mechanismbased on meteorological data in Huan County from 1958 to 2014, the seasonal and inter- annual variationtrend, periodic mutation characteristics and impact factors of the 57 years were analyzed. The results showedthat the inter- annual variability of evaporation was obvious, and the biggest evaporation of year and fourseasons occurred in the late 1950 s, the minimum evaporation appeared after 2000. The correlation analysisfound that the evaporation capacity was positively correlated with average wind speed, average temperature andsunshine duration, but negatively correlated with relative humidity, precipitation. Analysis indicated that themajor reason of evaporation decreasing in Huan County was the decrease of wind speed, and the second wasthe decrease of sunshine duration and the increase of precipitation.