Information Sharing and Using of SEBAL Spatial Evapotranspiration for Watershed Hydrological Modeling

Abstract

<abstract> <bold>Abstract.</bold> Evapotranspiration (ET) is an essential component in hydrologic cycle and becomes more important for healthy watershed management when considering climate change. This study is to estimate daily spatial ET of South Korea using Surface Energy Balance Algorithm for Land (SEBAL). SEBAL input data for the second half of 2012 were prepared from Moderate-resolution Imaging Sepctroradiometer (MODIS) Terra products. The MODIS daily surface reflectance (SR) and land surface temperature/emissivity (LST/E) of 500 m and 1000 m resolutions were used as the main data. Other data of daily wind speed, air temperature, and relative humidity data were prepared from seventy-six ground weather stations. The SEBAL ET was evaluated using measured ET by eddy covariance flux towersat forest area of YongdamDam watershed operated by K-water and at rice paddy of Cheongmicheon watershed by Hydrological Survey Center. The regression statistics (R²) with SEBAL and flux tower showed performance of 0.55 in Yongdam Dam and 0.58 in Cheongmicheon, respectively. The constant ‘a’ and ‘b’ for momentum transfer (z0m) was found to adjust for further calibration of SEBAL in South Korea.