Application of Scintillometer for Evaluating the Performance of GCOM-C ETindex Estimation Algorithm at a Forest Site
2019 年 24 巻 2 号 p. 27-32
詳細
2019 年 24 巻 2 号 p. 27-32
In this study, the accuracy of evapotranspiration estimated by the Global Change Observation Mission-Climate (GCOM-C) evapotranspiration index (ETindex) estimation model was evaluated using a scintillometer flux measurement dataset provided by the Idaho EPSCoR program, which was collected at an open lodgepole pine tree forest in eastern Idaho, United States. The scintillometer-measured sensible heat flux was quality-controlled, and evapotranspiration was computed using radiation data. The results of this analysis indicate that evapotranspiration was overestimated by the estimation model during summer. Owing to the overestimation in summer, the overall mean absolute error for the entire study period was 33 mm month-1, or 47% of the actual evapotranspiration. However, by conducting simple linear adjustment, the overall mean absolute error was improved to 14 mm month-1, or 19% of the actual ET. As the simple linear adjustment attempted in this study does not consider the seasonal trend in error, there is room to further improve the evapotranspiration estimation in the forest area by considering the seasonal effect during adjustment.
