Intercontinental Comparison of Evaporation Estimates

The success of estimating pan evaporation by three methods was evaluated by comparing estimates with measured values for nine locations in the United States, Africa, Europe, and Australia. The locations represent coastal, inland, humid, equatorial, high latitude, and high elevation locations. The Christiansen, Kohler-Nordenson-Fox, and Olivier methods were evaluated. Pan evaporation estimates by the Kohler, et al method fit measurements best over a wide range of conditions. The Christiansen method provides excellent estimates under some conditions. The Olivier method estimates show the poorest fit, but require the least input data. None of the three methods gives satisfactory estimates for all locations.