The Next Generation of Evaporation Pans

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A new, more accurate and precise way to measure open-water evaporation is needed, especially as the demand for water increases as the supply decreases (Phillips and others, 2013), impacting water amounts ranchers, farmers, cities, and environmental restoration efforts receive. The goal of this project is to finalize the design, test, and validate a new open-water evaporation method. This proposed research strives to produce a more accurate method for measuring evaporation on reservoirs and lakes with the accuracy of this new method being validated with a hemispherical evaporation chamber. More specifically, the goal of this research is to finalize the design of and deploy and test a floating evaporation pan, and then compare the evaporation results to more common and established methods like the Class A evaporation pan, energy-budget equations, and bulk-aerodynamic equations. This will be accomplished by completing the following three research objectives. • Finalize the design of a semi-submerged Floating Evaporation Pan (FEP) that will have an adjustable freeboard and a protective wave guard, and then test the design at Cochiti Lake. • Assess the accuracy of the FEP with a hemispherical evaporation chamber while deployed Cochiti Lake for one year and calculate evaporation with various equations using micrometeorological instrumentations attached to the FEP. • Compute and compare the volume of water evaporated on a monthly time step for the FEP, a nearby Class A evaporation pan, and common energy-budget-, temperature-, and aerodynamic-based equations over a year-long period. The completion of these objectives will determine the reliability, accuracy, precision, and improvement over current methods for the proposed technology.

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