Understanding the role of hydrologic model structures on evapotranspiration-driven sensitivity. Issue 9 (3rd July 2020)

• Record Type: Journal Article
• Authors: Jayathilake, Dilhani Ishanka; Smith, Tyler
• Is Part Of: Hydrological sciences journal. Volume 65:Issue 9(2020)
• Page Start: 1474
• Page End: 1489
• Publication Date: 2020-07-03
• Subjects: conceptual hydrologic models -- eco-hydrologic models -- potential evapotranspiration -- model performance -- model parameterization -- sensitivity; Hydrology -- Periodicals; 551.4805
• DOI: 10.1080/02626667.2020.1754421
• Languages: English
• ISSNs: 0262-6667

Abstract

ABSTRACT: Most conceptual hydrological models do not treat vegetation as a dynamic component. This study focuses on understanding the impact of model structural complexity on the sensitivity of hydrologic models to potential evapotranspiration forcing data. To achieve this, two classes of hydrologic models are examined: (1) lumped, conceptual rainfall–runoff models and (2) eco-hydrologic models. A sample of 57 US catchments, covering eight eco-regions, included in the MOPEX dataset is used. While streamflow simulation performance in complex models did not exhibit increased sensitivity to PET, actual evapotranspiration simulation performance showed greater sensitivity in energy-limited catchments. This analysis warns against using over-simplistic PET estimations in energy-limited catchments for eco-hydrologic models and for more complex conceptual hydrologic models. This is particularly true for streamflow-only calibrations that commonly fail to properly constrain physically based parameters. Ultimately, these results have the potential to inform data collection and model selection efforts to yield the greatest benefit.