Comparative assessment of evaporation models in algal ponds

The ability to predict water evaporation from shallow ponds is needed to accurately assess the water demand and costs of microalgae farming. This study assessed the accuracy of seven evaporation models available in the literature against experimental data collected in a raceway algal pond located in Narbonne, France. A theoretical `flat-plate' evaporation model and the Sartori model were identified as the most accurate models (errors of 14.2% and 9.2%, respectively, over a period of 274 days). As these two models require the mathematical determination of pond temperature, simulations were performed to determine if pond temperature could be substituted for air temperature to compute yearly evaporation estimates. Unfortunately, assuming that pond temperature was equal to air temperature caused significant inaccuracies on the yearly evaporation (e.g. up to 68% in an arid climate with the Sartori model). High-resolution co-modeling of evaporation and temperature is therefore required for accurate evaporation predictions.