Meteorological Influences on Reference Evapotranspiration in Different Geographical Regions: Fid-Bau Portal

Meteorological Influences on Reference Evapotranspiration in Different Geographical Regions

Mona Ghafouri-Azar / Sang-Il Lee

It is critical to understand how meteorological variables impact reference evapotranspiration $({ET}_{o})$ since meteorological variables have a different effect on ${ET}_{o}$ . This study examined the impact of meteorological variables on ${ET}_{o}$ on the Korean Peninsula under complex climatic and geographic conditions in order to understand how ${ET}_{o}$ and meteorological variables have changed over the past 42 years. Different geographical conditions were analyzed, including plains, mountains, and coastal areas on a seasonal and annual basis. ${ET}_{o}$ was estimated using the Penman-Monteith method by the Food and Agriculture Organization (FAO) using daily relative humidity $(RH)$ , solar radiation $(R_{s})$ , maximum temperature $(T_{\max})$ , minimum temperature $(T_{\min})$ , and wind speed $(W_{s})$ . According to the results, the maximum mean seasonal and annual ${ET}_{o}$ occurred on the southern coast, while the minimum occurred in the mountainous area and along the east coast. Seasonal ${ET}_{o}$ is highest in summer, and is lowest in winter for all regions. The investigation of meteorological variables on ${ET}_{o}$ revealed that the response varied by area, and the magnitudes of sensitivity varied by location and season. RH is the most critical meteorological variable to affect ${ET}_{o}$ in all seasons, except summer, when $T_{\min}$ is the most sensitive parameter. The results revealed that different regions showed different responses to the change in ${ET}_{o}$ by changing the meteorological variables. Meteorological variables affecting ${ET}_{o}$ differ with different geologic conditions and seasons. in mountainous areas revealed almost similar responses to the change in RH, $R_{s}$ , and $T_{\max}$ (±10% change in ${ET}_{o}$ ) during the spring season. However, for other regions, RH and $T_{\max}$ caused changes to ${ET}_{o}$ throughout, ranging from −15% to +20% in the plain area, −20% to +15% in the west and east coast, and −20% to +10% in the south coast. In addition, there were significant differences in parameter responses between regions and seasons, which was confirmed by the results.