关中地区夏玉米和冬小麦不同蒸发蒸腾量估算方法的研究

Study on Different Methods for Estimating Evapotranspiration of Summer Maize and Winter Wheat in Guanzhong Area

参考作物蒸发蒸腾量(ET0)是精准估算作物需水量、提高农田水分利用效率的重要依据。基于2013-2017年的田间试验数据以及相关气象观测资料,采用5种计算ET0的方法计算关中地区日平均ET0和年平均ET0,采用Origin对ET0及环境因子进行相关分析,使用标准误差估计(SSE)和决定系数r^2,在FAO-56 PM和其他4种简单替代方法之间进行比较。结果表明:对ET0和气象因子的标准分数的分析表明,ET测量值和5种方法的估计值均高度依赖于太阳辐射和温度,但与相对湿度和风速的关系较小。对5种ET0估算方法,即:FAO-56 Penman-Monteith(FAO-56 PM)、Penman-Monteith(PM)、Priestly-Taylor(PT)、Mankink(MK)和Hargreaves(HG)进行了评估。统计分析表明PM可代替FAO-56 PM方法来预测该地区的ET0值。这与作物蒸发蒸腾量(ETC)的准确估计直接相关,这也取决于作物生理特征和发育阶段、天气参数、环境条件和管理实践。

The reference crop evapotranspiration(ET0)is an important basis for accurately estimating crop water demand and improving farmland water use efficiency.Based on field experiment data of 2013-2017 and related meteorological observation data,five kinds of ET0 calculation method were used to calculate the average ET0 and annual average ET0 in Guanzhong region,the Origin software was adopted to conduct related analysis of ET0 and environmental factors,the standard error estimate(SSE)and determination coefficient r^2 were used to compare FAO-56 PM with four other simple alternatives.The results show that:the analysis of standard scores of ET0 and meteorological factors shows that the ET measurements and the estimates of the five methods are highly dependent on solar radiation and temperature,but have little relationship with relative humidity and wind speed.Five ET0 estimation methods,namely,FAO-56 Penman-Monteith(FAO-56 PM),Penman-Monteith(PM),Priestly-Taylor(PT),Mankink(MK)and Hargreaves(HG),were evaluated.Statistical analysis shows that PM can replace FAO-56 PM to predict ET0 value in this region.This is directly related to accurate estimates of crop evapotranspiration(ETC),which also depends on crop physiological characteristics and developmental stages,weather parameters,environmental conditions and management practices.