基于蒸渗仪实测的参考作物蒸散发模型北京地区适用性评价  

Applicability assessment of reference evapotranspiration models in Beijing based on lysimeter measurement

作　　者：袁小环[1] 杨学军[1] 陈超[1] 武菊英[1] 

机构地区：[1]北京草业与环境研究发展中心,农业部都市农业(北方)重点实验室,北京100097

出　　处：《农业工程学报》2014年第13期104-110,共7页Transactions of the Chinese Society of Agricultural Engineering

基　　金：北京市自然科学基金(6122010);北京市农林科学院青年基金(QN201120)联合资助

摘　　要：参考作物蒸散发（ET0,reference evapotranspiration）是计算植被耗水量、分析区域水分平衡、管理水资源的基本参数。由于区域间气象条件的差异,ET0模型在不同地区表现出不同的适用性。蒸渗仪实测是欧美地区评价参考作物蒸散发模型的经典方法,而中国尚少研究,华北地区未见报道。2012年生长季（4-10月）,应用自动称重式蒸渗仪实测高羊茅草坪蒸散评价了Penman-Monteith（FAO-56）、Hargreaves-Samani、Priestley-Taylor、Penman-van Bavel模型在北京地区的适用性。在2个蒸渗仪中建植冷季型高羊茅草坪,以获得ET0标准数据。试验地安装Dynamet气象站,自动测量并记录气象数据：空气温度、空气相对湿度、太阳总辐射和高度2m的风速,用于模型计算参考作物蒸散发。应用线性回归与均方根误差（RMSE）、一致性指数（d）2个指标评价模型的预测准确性。研究结果表明,太阳总辐射与月蒸散之间呈现较强的线性关系（R2=0.95,p=2.72×10^-7）,说明太阳辐射能量是驱动SPAC（soil-plant-atmosphere continuum）系统中水分从植被向大气运动的主要动力。随着时间尺度减小,模型的估算准确度降低。由于模型的输入参数不同,在ET0计算中出现了不同方向的偏差。月尺度上,Priestley-Taylor模型低估,而Penman-Monteith、Hargreaves-Samani和Penman-van Bavel模型高估了蒸散。日尺度上,Hargreaves-Samani模型和Penman-van Bavel模型略微高估了日蒸散,比率分别为1.0167和1.0526;Penman-Monteith模型和Priestly-Taylor模型低估了日蒸散,比率分别为0.8204和0.7593。时尺度上,除了Priestly-Taylor模型全部得出最低的数值,其余模型在不同天气类型下得出不同的计算结果。综合月、日、时3个时间尺度的评价结果,Penman-van Bavel是最准确的ET0计算公式,RMSE分别为0.63 mm/d（月）、1.43 mm/d（日）、0.087mm/h（时）,d值分别为0.96（月）、0.89（日）、0.87（时）。Penman-MoReference evapotranspiration（ET0） is the basic parameter for the vegetation evapotranspiration calculation, the regional water balance analysis, and the water resources management. The ET0 models have different adaptability for different regions because of the difference in meteorological conditions among regions. Measurement using lysimeter is the classical method for ET0 model evaluation in European and American areas, but is seldom used in China, and no research reported for North China. Assessment of four ET0 models, Penman-Monteith（FAO-56）, Hargreaves-Samani, Priestley-Taylor, and Penman-van Bavel were conducted in Beijing using tall fescue（Festuca arundinacea L.） turf evapotranspiration measurement by auto-weighing lysimeter during the growing season（April-October） of 2012. Two lysimeters were established in cold-season grass tall fescue for standard ET0. The weather station（Dynamet, Dynamax Co. Ltd.） was set up in the experiment site to measure and record automatically the meteorological data of air temperature, air relative humidity, solar radiation and wind speed at 2 meter height above ground for the ET0 calculation by the models. The linear regression and the root-mean-square error（RMSE） and the index of agreement（d） were used for assessing the prediction accuracy of the different models. The results indicated that the solar radiation showed a linear relationship（R2=0.95, p=2.72×10^-7） with the monthly reference evapotranspiration, indicating that the solar radiation energy was the main force to drive water from the vegetation to the atmosphere in SPAC system. The accuracy of the models declined with the time scale. The models showed different deviations in ET0 calculation because of the different parameters input. The monthly ET0 was underestimated by Priestley-Taylor model but overestimated by Penman-Monteith、Hargreaves-Samani and Penman-van Bavel models. For the daily ET0, Hargreaves-Samani and Penman-van Bavel models had a slight overestimation with the rate of 1.

关 键 词：蒸散发 模型 辐射 气象 高羊茅 

分 类 号：S161[农业科学—农业气象学]