Using satellite-based evapotranspiration estimates to improve the structure of a simple conceptual rainfall-runoff model

作者：Roy Tirthankar; Gupta Hoshin V; Serrat Capdevila Aleix; Valdes Juan B

来源：Hydrology and Earth System Sciences, 2017, 21(2): 879-896.

DOI：10.5194/hess-21-879-2017

Daily, quasi-global (50 degrees N-S and 180 degrees W-E), satellite-based estimates of actual evapotranspiration at 0.25 degrees spatial resolution have recently become available, generated by the Global Land Evaporation Amsterdam Model (GLEAM). We investigate the use of these data to improve the performance of a simple lumped catchment-scale hydrologic model driven by satellite-based precipitation estimates to generate streamflow simulations for a poorly gauged basin in Africa. In one approach, we use GLEAM to constrain the evapotranspiration estimates generated by the model, thereby modifying daily water balance and improving model performance. In an alternative approach, we instead change the structure of the model to improve its ability to simulate actual evapotranspiration (as estimated by GLEAM). Finally, we test whether the GLEAM product is able to further improve the performance of the structurally modified model. Results indicate that while both approaches can provide improved simulations of streamflow, the second approach also improves the simulation of actual evapotranspiration significantly, which substantiates the importance of making "diagnostic structural improvements" to hydrologic models whenever possible.

• 出版日期2017-2-14