A framework to evaluate the applicability of ET products in the southeastern coastal basins of China

Accurate estimation of evapotranspiration (ET) is crucial for watershed eco-environmental research and applicability of ET products in southeastern coastal basins of China needs to be evaluated. We proposed an improved evaluation framework for basin applicability of ET products. Based on assessing the overall rationality and correcting ET products using water balance method, the temporal dynamics of corrected products ET (ET_C) were assessed by dual-variable calibrated SWAT model. Application of this framework in three basins in southeastern coastal China showed that three corrected products ET were consistent in magnitude, but differed markedly in inter-annual and intra-annual variability. Compared with SWAT-ET, ET_{C_SSEBOP} exhibited a better performance in temporal dynamics, followed by ET_{C_FLDAS}, and ET_{C_MOD16A2} was the worst. The simulation performance of products on forestland ET was a potential influencing factor to these differences. The proposed assessment framework for ET products provided a more holistic assessment of their applicability, yielding more reliable results.