Question

How to calculate evaporation water body by using pan coefficient?

Answer 1

ReadsINTRODUCTION Because of its nature, evaporation from water surfaces is rarely measured directly, except over relatively small spatial and temporal scales (Jones 1992). Evaporation from water is most commonly computed indirectly by one or more techniques. These include pan coefficients × measured pan evaporation, water balance, energy balance, mass transfer, and combination techniques. The selection of the "best" technique to use for a particular computation is largely a function of the data availability, type or size of the water body, and the required accuracy of the estimated evaporation. The most commonly used method in the US for estimating evaporation from small, shallow water bodies, is to measure evaporation from a standard pan and then multiply by a coefficient. The purpose of this brief paper is to describe some principles involved in estimating evaporation with example data from large and small water bodies. Particular emphasis will be on practical procedures and techniques that professionals can use to estimate evaporation from shallow water bodies using pan evaporation and a combination equation using available weather data and/or new data collected specifically for estimating daily evaporation.
(PDF) Estimating evaporation from water surfaces. Available from: https://www.researchgate.net/publication/265749992_Estimating_evaporation_from_water_surfaces [accessed Nov 10 2018].