不同潜在蒸散发估算方法在汉江流域中上游地区的适用性研究

蒸散发是流域能量循环和水文循环的重要变量,准确估算蒸散发具有重要的现实意义。FAO56PenmanMonteith方法计算潜在蒸散发量时气象资料往往不易满足,同时,在提出形式简单且满足精度要求的其它估算方法时,缺乏足够全面的适用性分析。针对上述问题,基于汉江流域中上游地区12个气象站点1961-2013年的逐日气象资料,以FAO56Penman-Monteith方法估算的潜在蒸散发量作为参考标准,分别从不同的时间尺度和空间尺度对比分析了1种综合类方法、2种辐射类方法和3种温度类方法在汉江流域的适用性。结果表明,辐射类方法适用性最好,综合类方法次之,温度类方法适用性较差。其中Makkink方法和Priestley-Taylor方法在研究区的适用性最好,计算精度高,McCloud方法在研究区的适用性最差,误差较大。

The applicability of various potential evapotranspiration estimation methods in the middle and upper reaches of Hanjiang River Basin

As the potential evapotranspiration (PET) is one of the important factors in the energy cycle and hydrological cycle, the accurate estimation of PET has important practical significance. The FAO56-PM method can give efficient estimation of PET; however, its applicability is constrained as it requires a large amount of data. Different PET estimation methods have been proposed and the applicability of these methods should be tested before they are applied in a typical region. In this study, we attempted to examine the efficiency of 7 PET estimation methods in spatial and temporal dimensions in the upper and middle reaches of Hanjiang River Basin using the daily meteorological data during 1961-2013. The results showed that the radiation-based methods were the optimal choice, followed by the combination method, and the temperature-based methods were the least suitable choice for the PET estimation in the study area. Among these estimation methods, the Makkink method and the Priestley-Taylor method showed the best applicability and highest precision in the study area, while the McCloud method showed the worst applicability and largest error.