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参考作物蒸散量(ET0)是计算作物需水量的关键因子,目前计算ET0最准确的方法主要是FAO Penman-Monteith模型,但该模型需要大量的参数而在有些地区难以应用。为了寻求利用有限参数确定ET0的适用方法,将模拟蒸散仪(Simulated ETgage Atmometer)实测ET0值与FAO Penman-Monteith等7种常用的、参数需求不同的模型计算的ET0值进行了比较研究。结果表明:①模拟蒸散仪实测ET0值与FAO Penman-Monteith模型计算结果非常接近,说明绿洲灌区ET0可以用模拟蒸散仪直接测定,若参数齐全也可用FAO Penman-Monteith模型直接计算;②如果有效参数仅可满足Hargreaves模型计算需求,也可用该模型计算ET0,但在精确的灌溉设计和农田水量平衡测算中该模型计算的5—8月值需要降低5.2%;③建立了Jensen-Haise、FAO-17 Penman、FAO-24 Radia-tion等模型的修正模型,若有效参数仅能满足这些模型的计算需求,就可用这些修正模型准确计算试区ET0;④Makkink模型和Priestley-Taylor模型不能用于试区ET0的准确计算。
The reference crop evapotranspiration (ET0) is the key factor to calculate the crop water requirement. At present, the most accurate method for calculating ET0 is the FAO Penman-Monteith model. However, this model requires a large number of parameters and is difficult to be applied in some areas. In order to find a suitable method to determine ET0 using limited parameters, the ET0 values calculated by Simulated ETgage Atmometer measured ET0 value and FAO Penman-Monteith and other commonly used parameters with different requirements were compared. The results show that: ① ET0 measured by simulated evapotranspiration is close to that calculated by FAO Penman-Monteith model, which indicates that ET0 in oasis irrigation area can be directly measured by simulated evapotranspiration; if the parameters are complete, it can be directly calculated by FAO Penman-Monteith model; ② If valid parameters Which can only meet the calculation requirements of Hargreaves model and can also be used to calculate ET0. However, the calculated May-August value needs to be reduced by 5.2% in the accurate irrigation design and farmland water balance calculation. ③ The establishment of Jensen-Haise, FAO- 17 Penman and FAO-24 Radia-tion models. If the valid parameters can only meet the computing requirements of these models, these modified models can be used to accurately calculate the ET0. ④ The Makkink model and the Priestley-Taylor model can not be used in the test area ET0 accurate calculation.