Estimation of Local Evapotranspiration using Remotely Sensed Data based Model

Abstract:

Reasonable estimation of actual evapotranspiration is important for water resources planning and management even though the procedure for estimating actual evapotranspiration is costly and complicated. This study estimated actual evapotranspiration in several locations using the bio-meteorological version of the Priestley-Taylor, so called PT-JPL, and then compares with filed observed flux data. The PT-JPL is relatively simple and requires minimum number of observations for estimating local actual evapotranspiration. It is also advantageous that The PT-JPL has no calibration, tuning, or spin-up for local adjustment. Type and amount of surface vegetation need to be prescirbed into the estimation of actual evapotranspiration. The PT-JPL is eco-physiological theory based and description of surface vegetation is crucial. The satellite-collected normalized difference vegetation index (NDVI) and soil-adjusted vegetation index (SAVI) were used to describe the land surface characteristics. Meteorological information such as temperature, water vapor, radiation, and actual evapotranspiration was retrieved from AsiaFlux. The results show that the local actual evapotranspiration estimated by the PT-JPL is within reasonable accuracy. This study will assist to identify the relationship between particulate matters (PM) and drought in the near future.

Acknowledgement

This work was supported by the National Research Foundation of Korea (NRF-2017-2017001809)