Application of a simple finite difference model for estimating evaporation from open water

• Published in: Journal of hydrology (Amsterdam) Vol. 255; no. 1; pp. 253 - 259
• Main Authors: Finch, J.W, Gash, J.H.C
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 02.01.2002; Elsevier Science
• Subjects: Earth sciences; Earth, ocean, space; Energy balance; Evaporation; Exact sciences and technology; Hydrology. Hydrogeology; Modelling; Open water; Water resources; England; United Kingdom; Great Britain; Western Europe; Energy balance; Modelling; Evaporation; Open water; models; finite difference analysis; Europe; water resource management; reservoirs; temperature; energy balance; equilibrium; lakes; evaporation; methodology
• ISSN: 0022-1694; 1879-2707
• DOI: 10.1016/S0022-1694(01)00511-X

In estimating the evaporation from open water, the challenge is to accurately quantify the change in heat stored in the water body. A simple finite difference model is described and a comparison made between measured values of water temperature and evaporation, from a reservoir in southeast England, and the values predicted by an equilibrium temperature model. The values predicted by the new model are in excellent agreement with the measurements and are closer to the measured values than those predicted by the equilibrium temperature model. The difference in performance is attributed to improved methods used for calculating the net radiation and the wind function. The simpler formulation of the finite difference model is considered to offset the disadvantage of the greater number of calculations required.