参考作物蒸散量模型在林芝市的适用性分析

Applicability Analysis of Reference Crop Evapotranspiration Model in Nyingchi Region

为探究不同参考作物蒸散量(ET0)模型在西藏林芝市的适用性,整理了林芝市3个国家基本气象站的气象数据资料,以FAO推荐的Penman-Monteith(FAO 56PM)模型计算结果为标准,比较了4种ET0模型计算值的逐日变化规律,并进行模型的适用性评价。结果表明:Makkink、Irmark-Allen、HargreavesSamani和Priestley-Taylor 4种模型计算的ET0日变化趋势与FAO 56PM模型计算结果一致,均在年际间呈先增后减的变化规律,峰值与谷值均分别出现在6~7月、12月至次年1月。Makkink模型的计算精度最高,误差统计指标MAE、RMSE、NSE分别为0.28 mm·d^(-1)、0.34 mm·d^(-1)、0.84,Irmark-Allen模型次之,Hargreaves-Samani和Priestley-Taylor模型较差。各模型与FAO 56PM模型间线性相关关系显著,校正后的Hargreaves-Samani、Priestley-Taylor、Irmark-Allen的MAE、RMSE、NSE值分别在0.11~0.18 mm·d^(-1)、0.15~0.30 mm·d^(-1)、0.87~0.97之间,且散点均匀的分布于y=x趋势线的两侧。研究认为,Makkink模型及校正后的Irmark-Allen、Hargreaves-Samani和Priestley-Taylor模型在林芝市均具有较好的适用性。

In order to clarify the applicability of the calculation model for reference crops evapotranspiration(ET0)in the Nyingchi Region of Tibet,four ET0 models were evaluated with the long series of meteorological data from three meteorological stations to compare the daily variation of ET0.The Penman-Monteith(FAO 56PM)equation recommended by FAO was used as a standard to evaluate the applicability of four models.Results showed that the variation trends of daily scale ET0 calculated by Makkink,Irmark-Allen,Hargreaves-Samani and Priestley-Taylor model were all consistent with the FAO 56PM model,which increased firstly and then decreased during the inter-annual period.The maximum value of ET0 appeared in June to July,and the minimum appeared in December to January of the following year.The error statistical indicators of MAE,RMSE,and NSE values of Makkink model were 0.28 mm?d-1,0.34 mm?d-1 and 0.84,respectively,with the highest simulation accuracy.The Irmark-Allen model had lower simulation accuracy,and the Hargreaves-Samani and Priestley-Taylor model had the poorest performance.The linear correlation between each model and the FAO 56PM model was significant.After correction,the MAE,RMSE,and NSE values of the Hargreaves-Samani,Priestley-Taylor,and Irmark-Allen models were between 0.11 to 0.18 mm?d-1,0.15 to 0.30 mm?d-1,and 0.87 to 0.97,and the scatter plots were evenly distributed on both sides of the tendency equation“y=x”.Therefore,it is believed that the Makkink model and the corrected Irmark-Allen,Hargreaves-Samani,and Priestley-Taylor models all have applicability in Nyingchi area.