Gaussian Process Emulation of Spatio-temporal Outputs of a 2D Inland Flood Model

James Donnelly, Soroush Abolfathi, Jonathan Pearson, Omid Chatrabgoun, Alireza Daneshkhah

Research output: Contribution to journalArticlepeer-review

79 Citations (Scopus)
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Abstract

The computational limitations of complex numerical models have led to adoption of statistical emulators across a variety of problems in science and engineering disciplines to circumvent the high computational costs associated with numerical simulations. In flood modelling, many hydraulic and hydrodynamic numerical models, especially when operating at high spatiotemporal resolutions, have prohibitively high computational costs for tasks requiring the instantaneous generation of very large numbers of simulation results. This study examines the appropriateness and robustness of Gaussian Process (GP) models to emulate the results from a hydraulic inundation model. The developed GPs produce real-time predictions based on the simulation output from LISFLOOD-FP numerical model. An efficient dimensionality reduction scheme is developed to tackle the high dimensionality of the output space and is combined with the GPs to investigate the predictive performance of the proposed emulator for estimation of the inundation depth. The developed GP-based framework is capable of robust and straightforward quantification of the uncertainty associated with the predictions, without requiring additional model evaluations and simulations. Further, this study explores the computational advantages of using a GP-based emulator over alternative methodologies such as neural networks, by undertaking a comparative analysis. For the case study data presented in this paper, the GP model was found to accurately reproduce water depths and inundation extent by classification and produce computational speedups of approximately 10,000 times compared with the original simulator, and 80 times for a neural network-based emulator.
Original languageEnglish
Article number119100
Number of pages17
JournalWater Research
Volume225
Early online date14 Sept 2022
DOIs
Publication statusPublished - 15 Oct 2022

Bibliographical note

This is an open access article under the CC BY licence.

Keywords

  • Flood prediction
  • LISFLOOD-FP
  • Gaussian process emulator
  • Spatiotemporal outputs
  • Dimensionality reduction
  • Extreme event simulation

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