汉江上游流域潜在蒸散量敏感性分析

为研究全球变暖背景下汉江上游流域潜在蒸散量的变化特征,根据汉江上游流域1960—2015年汉中、石泉和安康3个气象站的逐日实测气象数据,采用彭曼-蒙蒂斯方程计算逐日潜在蒸散量ET_0。应用敏感性公式计算ET_0对5个主要气象因子的敏感系数,并结合气象因子的多年相对变化分析ET_0变化成因。结果表明:受太阳周年运动及地形等地理要素的共同影响,汉江上游不同气象因子及ET_0的年内分布不一;汉江上游ET_0对相对湿度最为敏感,各气象因子年敏感系数多呈显著下降趋势,敏感程度均达到"中"以上等级;ET_0同气象因子表现出复杂非线性关系,日照是汉中站ET_0变化的主导气象因子,石泉和安康站ET_0变化的主导气象因子是相对湿度。

Sensitivity analysis of potential evapotranspiration in upper Hanjiang River Basin

In order to study the variation characteristics of potential evapotranspiration in the upper Hanjiang River Basin under the background of global warming, based on the daily observed meteorological data of Hanzhong, Shiquan and Ankang meteorological stations in the upper reaches of the Hanjiang River from 1960 to 2015, the daily potential evapotranspiration(ET₀)was calculated by Penman-Monteith equation, and the sensitivity formula was used to calculate the sensitivity coefficient of ET₀ to five main meteorological factors. And the causes of ET₀ variation were analyzed in combination with the relative changes of meteorological factors over the years. The results show that the distribution of meteorological factors and ET₀ in the upper Hanjiang River Basin within the year is different due to the combined influence of geographical factors such as solar annual movement and topography. ET₀ in the upper Hanjiang River Basin is most sensitive to relative humidity. The annual sensitivity coefficients of meteorological factors show a significant downward trend, and the sensitivity reaches the "middle" level or above. The relationship between ET₀ and meteorological factors is complex and non-linear. Sunshine is the dominant meteorological factor of ET₀ variation at Hanzhong Station. Relative humidity is the dominant meteorological factor of ET₀ variation at Shiquan and Ankang Station.