ET_0计算模型及其主要输入因子的影响分析评估

ET_0 Calculates the Influence of Models and its Major Inputted Factor to Analysis Evaluation

采用内蒙古中部呼和浩特1961—2003年，43年的气象资料，对计算ET0的修正Penman模型与MontdthPenman模型中输入的主要气象因子（气温、风速、湿度、太阳辐射或日照）分析评估。结果显示：单纯的模型计算对比难以评价哪一种模型更适合中国复杂的地理及气候环境，必须利用Lysmiets等实验结果对各种模型进行率定考核。同时ET0模型中，输入的某些主要气象因子对ET0值的影响非常明显：不同地区、不同的作物、不同生长期，净辐射计算Angstrom公式中的a、b值应不同；年平均气温增加2．1℃时，北方干旱、半干旱区4—10月份ET0值增加3．9％-5．2％；当风速增加20％时，作物生育期内（4—10月份）ET0增加3．9％-8．0％，春夏之交4—6月份ET0增加值占全生育期的61．9％；而半干旱区相对湿度的改变对ET0值影响很小。对二种模型中输入各因子影响程度的分析评估有助于ET0的认识深化及应用推广。

This paper adopts the meteorological data from 1961 to 2003, 43 years , of huhhot meteorological station in Inner Mongolia, for calculating the ETo of modified Penman model and Monteith-Penman model that inputted major meteorological factors （ temperature, wind speed, humidity, solar radiation or sunshine ） analysis evaluation. Show as a result： Simple model calculation contrast is hard to appraise which kind of model more suit climate environment and the geography with complex China, must carry out rate by using the experiment results such as Lysmiets for various models to check. At the same time, it is very obvious that ETo calculate the influence and that some major meteorological factors value to ETo that inputted in model. Different growth season , different area and different crop are expected , in completely radiometer calculate, value of a and b of Angstrom formula should be different. Year in average temperature increase 2.1℃, north is arid , half arid district from April to October ETo value increase ranging from 3.9% to 5.2%. When wind speed increases in 20% of crop growth season （ from April to October）, ETo win vary in a range of 2.9% - 8.0%. Value added of ET0 from April to June takes the 61.9% of all crop growth season. And the influence of half arid district relative humidity that change value to ETo is very litfie. For each factor inputted influence of two models, it is extending that the analysis evaluation of level is helpful for the knowledge of ETo to deepen and apply.