A Novel Approach for Evaluation of Hydrodynamic Model by Integrating
Performance for Multiple Variables
Abstract
Large-scale river hydrodynamic model act as fundamental tool for many
scientific applications related to water cycle, biogeochemistry, and
carbon cycle. Even though process representation in the physically based
hydrodynamic models has improved significantly in recent times, due to
many error sources the uncertainty reduction and evaluation remains a
key issue. Previously most of the research focused on the evaluation of
hydrodynamic model considering single variable only i.e., discharge due
limitations related to models and data availability. The recent advances
in hydrodynamic modelling and remote sensing helped to overcome
limitation. Some recent studies performed calibration and validation
considering multiple variables but were unable to integrate them into a
single evaluation score due to different spatial and temporal dimension
of variables and thus make it hard to judge the overall performance.
Here, we have evaluated the performance of Catchment-based Macroscale
Floodplain (CaMa-Flood) hydrodynamic model over Amazon basin considering
multiple variables i.e., discharge (Q), water surface elevation (WSE)
and flooded area (FA) for a topography data multi-error removed improved
terrain (MERIT) DEM. We proposed an evaluation method and introduced a
metric “overall basin skill score” (OSK) to integrate the performances
due to multiple (three here) variables considering their spatial
distribution via a sub-basin approach and provide the evaluation on a
scale of 0 to 1. The integrated method showed the robustness in the
method and able to detect the best river channel depth parameter set
with maximum OSK of 0.57, whereas the evaluation using single variable
proved inadequate due to different sensitivity of variables and maximum
metric score were obtained for many parameters sets. The proposed method
enables a balanced evaluation of different variables and proved useful
to integrated multivariable model evaluation with reducing the chances
of getting the right results due to wrong reasons. Preprint related to
this work: https://doi.org/10.1002/essoar.10506596.1