2012年太湖蒸发量变化特征及蒸发模型评估研究

Variability of Evaporation from Lake Taihu in 2012 and Evaluation of a Range of Evaporation Models

湖泊蒸发是全球能量分布,水文循环的重要组成部分,同时是气候及生态系统环境变化的指示因子。运用太湖湖上观测平台大浦口站2012年涡度相关数据分析了太湖蒸发量的月变化及日变化特征,并评估了11种蒸发模型。结果表明:太湖2012年总蒸发量为1066.2 mm。潜热通量是太湖净辐射能量分配中的主导项,2012年太湖地区潜热通量占净辐射通量的91.9%。2~7月为太湖水体储热阶段,当净辐射在7月达到最大值时,蒸发值也达到最大值;净辐射8月开始减少,至12月达到最小值,期间湖体储热释放,使得蒸发量在2月才达到最小值。采用涡度相关系统观测太湖蒸发量的数据评估了11种蒸发模型,分别从年蒸发总量和蒸发量月变化特征来探讨模型对于太湖蒸发量计算的适用性,其中以波文比能量平衡模型表现最好,与涡度相关观测值的相关系数为0.99,中心化均方根误差为4.50 mm month^(-1)。

Evaporation is an important component of the distribution of energy and the hydrological cycle on the global scale, and is also an indicator of climatic, environmental, and ecosystem changes. In this paper, eddy covariance data from Dapukou station in 2012 are used to analyze the seasonal and diurnal variation of evaporation across Lake Taihu. In addition, 11 evaporation models are also evaluated. The results show that the total evaporation from Lake Taihu in 2012 was 1066.2 mm. The latent heat flux was the dominant term of the net radiation energy, which occupied about 91.9% in 2012. The water body stores heat in the period from February to July, after which the net radiation increases to a maximum in July, and evaporation also reaches a maximum. Thereaiter, net radiation reduces to a minimum in December, stored heat is released, and evaporation reaches a minimum in February. Comparing 11 evaporation models with the eddy covariance data to evaluate their performance with respect to the evaporation from Lake Taihu, we discuss the total annual evaporation and evaporation variation. The Bowen ratio energy budget model shows the best performance, because the correlation coefficient between the simulation value and the observation is 0.99, and the centered-mean-square error is 4.50 mm month-1.