Pan evaporation is increased by submerged macrophytes

[摘要] The topic of evaporation estimates is fundamental toland-surface hydrology. In this study, FAO-56 Penman–Monteith equation(FAO56–PM), multiple stepwise regression (MLR), and Kohonen self-organisingmap (K–SOM) techniques were used for the estimation of daily pan evaporation( E p ) in three treatments, where C was the standard class A pan with topwater, S was a pan with sediment covered bottom, and SM was class A pancontaining submerged macrophytes ( Myriophyllum spicatum , Potamogeton perfoliatus , and Najas marina ), at Keszthely, Hungary, in asix-season experiment, between 2015 and 2020. The modelling approachincluded six measured meteorological variables. Average E p varied from0.6 to 6.9 mm d −1 for C, 0.7 to 7.9 mm d −1 for S, and from 0.9to 8.2 mm d −1 for SM during the growing seasons studied. Correlationanalysis and K–SOM visual representation revealed that air temperature andglobal radiation had positive correlation, while relative humidity had anegative correlation with the E p of C, S, and SM. The results showedthat the MLR method provided close compliance ( R 2 =0.58 –0.62) with theobserved pan evaporation values, but the K–SOM method ( R 2 =0.97 –0.98)yielded by far the closest match to observed evaporation estimates for allthree pans. To our best knowledge, no similar work has been published previously usingthe three modelling methods for seeded pan evaporation estimation. The current study differs from previous evaporation estimates by usingneural networks even with those pans containing sediments and submergedmacrophytes. Their evaporation will be treated directly by K–SOM, in whichthe modelling is more than the simple E p of a class A pan filled with cleantap water.

[学科分类] 妇产科学