Assessment of uncertainty in estimating the evaporation from the Curonian Lagoon

Abstract

In this study, three methods of evaporation estimation (temperature-based ETo [evapotranspiration] equations, radiation-based ETo equations, and mass-transfer based ETo equations) were applied to calculate the evaporation from the Curonian Lagoon. Estimation of evaporation by various methods showed that the annual mean of evaporated water from this shallow water basin during 1971–2011 ranged between 512–643 mm (average: 586 mm). The study revealed that Thornthwaite, Schendel, and Vikulina equations gave the most accurate assessment and the lowest uncertainties of evaporation (R of the calculated and the measured data ranged between 0.78–0.96). The value of evaporation depended on differences in estimated water surface area of the basin. The calculated evaporation using a constant surface area differed more than 10% from the one estimated according to the relationship between surface area and water level. However, these differences are minor in the context of the total water balance of the Curonian Lagoon, comprising only 0.06%–0.31% of the total water volume.