Evaluation of Meteorological Data-Based Models for Potential and Actual Evapotranspiration Losses Using Flux Measurements

Abstract

Evapotranspiration is a key process within the hydrological cycle, so it requires an accurate assessment. This work aims at assessing monthly scale performances of six meteorological data-based methods to predict evapotranspiration by comparing model estimates with observations from six flux tower sites differing for land cover and climate. Three of the proposed methodologies use a potential evapotranspiration approach (Penman, Priestley-Taylor and Blaney-Criddle models) while the additional three an actual evapotranspiration approach (the Advection-Aridity, the Granger and Gray and the Antecedent Precipation Index method). The results show that models efficiency varies from site to site, even though land cover and climate features appear to have some influence. It is difficult to comment on a general accuracy, but an overall moderate better performance of the Advection-Aridity model can be reported within a context where model calibration is not accounted for. If model calibration is further taken into consideration, the Granger and Gray model appears the best performing method but, at the same time, it is also the approach which is mostly affected by the calibration process, and therefore less suited to evapotranspiration prediction tools dealing with a data scarcity context.

Comparing Evapotranspiration Estimates from the GEOframe-Prospero Model with Penman–Monteith and Priestley-Taylor Approaches under Different Climate Conditions

“…Future research directions of the present work are threefold. From one side, the PS model can be compared to meteorological data-based approaches for the prediction of actual ET, such as the Antecedent precipitation index model or the Advection aridity model [37,76], which are more effective at reproducing the ET fluxes than the potential ET models proposed in the present study. On the other side, since the PS model returns an ET overestimation during the energy-limited periods (particularly evident in GL-Zah site), a threshold mechanism could be applied in order to improve the overall prediction.…”

“…In addition to the Prospero model, two classical ET models were implemented as components in GEOframe and compared to the results provided by Prospero for each of the previously described sites. These models were selected, among many others belonging to the same classes, since they were widely used in previous studies and returned very acceptable and accurate results [75,76]. In addition, they require a small number of meteorological variables as input parameters, which are easily available from local weather stations.…”

Mechanisms and Empirical Modeling of Evaporation from Hardened Surfaces in Urban Areas

“…Soil moisture content is recorded by soil moisture probe, rainfall is recorded by rainfall barrel, RH and temperature are recorded by temperature and humidity self-recording instrument. There are other meteorological factors that affect the evaporation process, such as wind speed, net radiation, and so on [ 29 , 30 ]. These meteorological data are derived from the monitoring data of the weather station.…”