Simulation of Actual Evapotranspiration and Evaluation of Three Complementary Relationships in Three Parallel River Basins

Abstract

Based on observed precipitation and runoff data, monthly actual evapotranspiration (ET a ) was calculated by the hydrological budget balance method in the three parallel river basins. The performance of three developed complementary relationship methods, the nonlinear advection-aridity (non-AA) method, generalized complementary relationship method (B2015), and sigmoid generalized complementary function (H2018), on simulating ET a were evaluated. The evaluation results showed that three methods were able to accurately simulate monthly ET a series. The Nash-Sutcliffe e ciency coe cient between the monthly ET a simulated by the non-AA, B2015, and H2018 methods and the water-balance-derived ET a were 0.74, 0.78, and 0.79, respectively. The correlation coe cient were 0.84, 0.89, and 0.90, respectively. And the root mean square errors were 10.76 mm mon − 1 , 10.01 mm mon − 1 , and 9.78 mm mon − 1 , respectively. The ET a increased spatially from upstream region to downstream region at catchment scale. Annual ET a simulated by the non-AA, B2015 and H2018 models showed signi cant increasing trends during 1956-2018 in the basins, with the increasing magnitudes of 1.53 mm/a, 1.66 mm/a and 1.47 mm/a, respectively. Research on the in uence between meteorological factors and ET a showed that there was a positive correlation between ET a and precipitation, temperature, wind and sunshine hours, with the average correlation coe cient of 0.40 0.64 0.63 and 0.72, respectively. The value between ET a and relative humidity was − 0.38. The ET a in the basins was highly sensitive to temperature, wind speed and sunshine hours, with the average sensitivity coe cient of 0.26, 0.21 and 0.27, respectively. And moderately sensitive to relative humidity, with a sensitivity of -0.18.

Comparative evaluation of four actual evapotranspiration models over different ecosystems and climate zones in China

“…Although a considerable amount of model comparison work has been undertaken, there are still some drawbacks to intercomparison and assessment of model performance. First, the existing work focuses on comparisons between models of the same type or variants of the same model (Yang et al 2015;Bhattarai et al 2016;Yan & Gao 2021;Jiang & Liu 2022;Peddinti & Kisekka 2022). Second, the ET models are usually assessed using flux sites located in America or Europe (Ershadi et al 2014;Bhattarai et al 2016;Bu et al 2021;Hu et al 2021;Melo et al 2021).…”