Influence of Meteorological Variable Combinations on Reference Evapotranspiration Estimated by the FAO56 Penman-Monteith Method
2016 年 7 巻 2 号 p. 147-153
詳細
2016 年 7 巻 2 号 p. 147-153
An estimate of potential evapotranspiration (PET) is typically required for rainfall runoff modeling, and such as estimate of PET is often determined from use of the Penman-Monteith (PM) method using air temperature, humidity, wind speed, solar radiation and sunshine hours data. This method is recommended by the FAO and used widely across the world. The estimated PET is known to vary depending on the combination of meteorological data used in the PM equation. For example, PET can be estimated by using wind speed and air temperature data only, or by using all five meteorological data. There have been no cases that were examined regarding how combinations of the five data influence estimated PET for the Asian Monsoon region. Air temperature, wind speed, solar radiation, sunshine hours and humidity were measured and recorded at ten-minute intervals for three years at a weather station in the Minami-Soma City, Fukushima Prefecture, Japan. The daily PET was estimated for the 13 combinations of the five data. It was found that PET is overestimated when the solar radiation is not included in the combination. The above results show that data on the solar radiation are indispensable for PET estimation that uses the PM equation in the Asian Monsoon region.
