Vol. 122, No. 1 * Pages 1–99 * Januar - March 2018

DOI:10.28974/idojaras.2018.1.4

A Class A pan (C) evaporation (E_p) study was conducted at the Agrometeorological Research Station of Keszthely, in the growing season of 2016. Some of the evaporation pans were implemented with freshwater aquatic macrophytes (Myriophyllum sp., Potamogeton sp.,and Najas sp.) (P_s) and sediment covered bottom (S). The applied macrophytes were the predominant species of Keszthely Bay (Balaton Lake). Reference (E_o) afterShuttleworthand reference evapotranspiration (ET_o) after Penman-Monteith (FAO-56 formula) were also included for the E study. Of pre-selected four investigated variables, air temperature and air humidity impacted E_p of treated Class A pans the most. Cumulative E_p values for 2016 were 363.1, 427.7, and 461.5 mm in C, S, and Ps, respectively. There was no difference in measured cumulative E_p of P_s (461.5 mm) and computed ET_o (472.1 mm) during the studied season.
On the basis of a simplified water budget, E rate of Keszthely Bay increased with 16.9%, when macrophytes and sediment cover were accounted. It is equivalent to 264,000,000 m³ water in Keszthely Bay’s E estimation. Simple E approach - when lake’s components, such as submerged macrophytes and sediment cover were also accounted - could extend the accuracy of natural lake’s E estimation in a broader circle than earlier.