A comparison between measured and modelled open water evaporation from a reservoir in south-east England

Estimates of evaporation from large open water bodies are required for a variety of purposes in water resource management. The equilibrium temperature approach provides a means of taking into account the heat storage in the water body. The evaporation predicted by a model based on this method is tested against measured evaporation from a reservoir at Kempton Park, UK. The evaporation and water temperature predicted by the model are in good agreement with the measurements. The mean annual evaporation is predicted to almost the same accuracy as the measurements. Estimates of the monthly predicted evaporation have root mean square errors about three times those of the measurements. The error in the mean annual evaporation estimated without taking the heat storage into account is 16%. Copyright (C) 2001 John Wiiey & Sons, Ltd.