Evaporation From Six Water Bodies of Various Sizes in East Asia: An Analysis on Size Dependency

Abstract

AbstractOne pond and five lakes in East Asia with area from 0.05 to 3,000 km2 were comparatively investigated to reveal the size‐dependency of the evaporation and its radiation and aerodynamic contributions. The available energy controls on the annual evaporation are independent on the sizes of the six water bodies, but the ratio of evaporation to Penman's open water evaporation decreases with areas from almost unity at the small pond to around 0.8 at the two large lakes. The aerodynamic related parameters of three combination equations can be well represented by the water body areas with a power law, which is attributed to the decreasing mass transfer coefficient with the fetch of the water body. The increasing size‐dependent wind speed offsets the effect of mass transfer coefficient, making the energy partitioning and evaporation rate size independent. Results imply that the energy‐based equations can be used for evaporation without considering the water body size in the study area. The size‐dependent parameters of the combination equations are required to be further investigated with more lakes.