Energy and water balance of a treatment wetland under mediterranean climatic conditions

During 2013-2014 period, the surface renewal (SR) - energy balance (EB) method combined with the water balance approach was adopted to define the energy and water budget of a treatment wetland (TW) in Eastern Sicily (Italy). The main objective was to evaluate the differences between energy and water balances and understand the underlining mechanisms of environmental control. Results shown that the seasonal variation in evapotranspiration (ET) had similar trend as the seasonal variation of leaf area index (LAI) and net radiation (R-n). During the study period, the daily rate of ET by EB ranged from -0.1 mm d(-1) to 9.3 mm d(-1), with a total ET of about 1837 mm in 17 months. The crop coefficient K-c (e.g. obtained using the FAO-56 mean K-c approach) for the TW ranged from 0.5 to 2.4, with a mean annual value of 1.24. On a 10-day mean basis, ET fluxes from the TW water balance were 15% higher than ET by EB.