摘要
基于涡度相关系统测量值和小气候观测资料,比较分析了Penman、FAO Penman-Monteith和Priestley-Taylor 3个模型对三江平原大豆田蒸散量的模拟效果.结果表明：3个模型参数采用常数时模拟值均大于测量值,尤以Penman模型最为明显,平均高估174.6％.Penman和FAO Penman-Monteith模型模拟效率均小于0,表明其模拟效果较差,不能用于估算大豆田间蒸散量.Penman和FAO Penman-Monteith模型的作物系数Kc值与叶面积指数之间呈显著正相关关系,与饱和水汽压差之间呈显著负相关关系;Priestley-Taylor模型α值与叶面积指数和风速之间均呈显著正相关关系,与饱和水汽压差之间呈显著负相关关系.依据多元线性回归方程修正Kc或α值后,Penman、FAO Penman-Monteith和Priestley-Taylor模型估算精度均明显提高,平均偏差变化范围为-0.10～0.00 mm·d-1,均方根误差均为0.67 mm·d-1,模拟效率均为0.61.方差分析进一步表明3个模型模拟结果没有显著性差异,但相对而言,Priestley-Taylor模型的截距、斜率和平均偏差略优于其他2个模型,因此Priestley-Taylor模型修正式是估算三江平原大豆田实际蒸散量的最优模型.
Based on the eddy covariance measurements and microclimate observational data available, comparison was done between the Penman, FAO Penman-Monteith （PM）, Priestley-Taylor （PT） models in accuracy of simulating evapo- transpiration of soybean field in the Sanjiang Plain. Results show that the values of evapotranspiration （ET） simulated with the models were all higher than the measured one when constants were adopted as parameters in modeling. The Penman model was in particular, being on average 174.6% higher. And the Penman and PM models both fell below zero in model- ing efficiency （EF）, which indicated that the two models were too poor in estimation accuracy to be used to predict actual ET of soybean field. In the Penman and FAO PM models, crop coefficient （Kc） was positively related to leaf area index （ LAI）, but negatively to saturated vapor pressure difference （VPD）, both at an extremely significant level; and in the PT model, o~ value was also positively related to LAI and wind speed and negatively to VPD, both at an extremely significant level, too. With Kc and a modified with the multiple linear regression equation, the three models improved estimation ac- curacy markedly, with mean bias error （MBE） ranging from -0. 10 to 0.00 mm· d-x, and root mean square errors （RMSE） and EF being 0. 67 mm · d-1 and 0. 61, respectively. ANOVA further indicated that no significant difference ex- isted between the three models in simulated value, but relatively speaking, the PT model was slightly superior to the other two in intercept, slope and MBE. Therefore, the modified PT model is an optimal one among the three for the use of esti- mating ET over soybean field in the Sanjiang Plain.
出处
《生态与农村环境学报》
CAS
CSCD
北大核心
2014年第1期50-56,共7页
Journal of Ecology and Rural Environment
基金
高原大气与环境四川省重点实验室开放基金(PAEKL-2010-K3)
成都信息工程学院科研基金(2009JY0117
KYTZ201010)
关键词
蒸散模型
作物系数
α值
大豆田
三江平原
evapotranspiration model
crop coefficient
a value
soybean field
the Sanjiang Plain
