Abstract
We here present GLOFRIM, a globally applicable computational framework for integrated hydrological-hydrodynamic modelling. GLOFRIM facilitates spatially explicit coupling of hydrodynamic and hydrologic models and caters for an ensemble of models to be coupled. It currently encompasses the global hydrological model PCR-GLOBWB as well as the hydrodynamic models Delft3D Flexible Mesh (DFM; solving the full shallow-water equations and allowing for spatially flexible meshing) and LISFLOOD-FP (LFP; solving the local inertia equations and running on regular grids). The main advantages of the framework are its open and free access, its global applicability, its versatility, and its extensibility with other hydrological or hydrodynamic models. Before applying GLOFRIM to an actual test case, we benchmarked both DFM and LFP for a synthetic test case. Results show that for sub-critical flow conditions, discharge response to the same input signal is near-identical for both models, which agrees with previous studies. We subsequently applied the framework to the Amazon River basin to not only test the framework thoroughly, but also to perform a first-ever benchmark of flexible and regular grids on a large-scale. Both DFM and LFP produce comparable results in terms of simulated discharge with LFP exhibiting slightly higher accuracy as expressed by a Kling-Gupta efficiency of 0.82 compared to 0.76 for DFM. However, benchmarking inundation extent between DFM and LFP over the entire study area, a critical success index of 0.46 was obtained, indicating that the models disagree as often as they agree. Differences between models in both simulated discharge and inundation extent are to a large extent attributable to the gridding techniques employed. In fact, the results show that both the numerical scheme of the inundation model and the gridding technique can contribute to deviations in simulated inundation extent as we control for model forcing and boundary conditions. This study shows that the presented computational framework is robust and widely applicable. GLOFRIM is designed as open access and easily extendable, and thus we hope that other large-scale hydrological and hydrodynamic models will be added. Eventually, more locally relevant processes would be captured and more robust model inter-comparison, benchmarking, and ensemble simulations of flood hazard on a large scale would be allowed for.
Original language | English |
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Pages (from-to) | 3913-3929 |
Number of pages | 17 |
Journal | Geoscientific Model Development |
Volume | 10 |
Issue number | 10 |
DOIs | |
Publication status | Published - 27 Oct 2017 |
Funding
Acknowledgements. This study was financed by the EIT Climate-KIC programme under project title “Global high-resolution database of current and future river flood hazard to support planning, adaption and re-insurance”. We also want to acknowledge the contributions of Climate-KIC and University of Bristol to realize a research stay at the University of Bristol. Special thanks are reserved for Arthur van Dam and Herman Kernkamp from Deltares for their support in applying Delft3D Flexible Mesh and Edwin Sutanudjaja for PCR-GLOBWB advice. Last, we want to express our gratitude to an anonymous reviewer and Dai Yamazaki for evaluating a previous version of the manuscript and providing invaluable feedback.
Funders | Funder number |
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EIT Climate-KIC |