Global Sensitivity Analysis for the Gironde Estuary Hydrodynamics with TELEMAC2D

Vanessya Laborie; Nicole Goutal; Sophie Ricci; Matthias De Lozzo; Yoann Audouin; Philippe Sergent

doi:10.29007/6tgm

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Global Sensitivity Analysis for the Gironde Estuary Hydrodynamics with TELEMAC2D

8 pages•Published: September 20, 2018

Vanessya Laborie, Nicole Goutal, Sophie Ricci, Matthias De Lozzo, Yoann Audouin and Philippe Sergent

Abstract

This paper presents a global sensitivity analysis study applied to a TELEMAC2D nu- merical flood forecast model of Gironde estuary which aims at identifying which input variables should be better described for water levels to be better simulated and forecasted. A variance sensitivity study (ANOVA) was carried out, by calculating Sobol’ indices for all numerical parameters (wind influence coefficient, Strickler friction coefficients for 4 zones) and time-dependent forcings of the model (rivers discharges and maritime boundary con- ditions). It led to the identification of parameters and forcings to which the model is most sensitive for each area of the estuary. Sobol’ indices for 2003 event show a predominance of the influence of the maritime boundary conditions and of Strickler coefficients all along the estuary. A mesh convergence study shows that the results don’t depend on the mesh. Moreover, a special focus on the eigenvalues of the tide signal correlation error function shows no predominance of one mode on the other. These first results are currently used to implement a sequential ensemble Kalman filter improving both the state of the system and the maritime boundary condition and optimizing the friction coefficients over the Gironde estuary.

Keyphrases: Ensemble Kalman Filter, Gironde Estuary, global sensitivity analysis, Karhunen-Loeve decomposition, Sobol’ indices, Telemac2D, Time-dependent inputs

In: Goffredo La Loggia, Gabriele Freni, Valeria Puleo and Mauro De Marchis (editors). HIC 2018. 13th International Conference on Hydroinformatics, vol 3, pages 1096--1103

Links:	https://easychair.org/publications/paper/BC7f
	https://doi.org/10.29007/6tgm

BibTeX entry

@inproceedings{HIC2018:Global_Sensitivity_Analysis_for,
  author    = {Vanessya Laborie and Nicole Goutal and Sophie Ricci and Matthias De Lozzo and Yoann Audouin and Philippe Sergent},
  title     = {Global Sensitivity Analysis for the Gironde Estuary Hydrodynamics with TELEMAC2D},
  booktitle = {HIC 2018. 13th International Conference on Hydroinformatics},
  editor    = {Goffredo La Loggia and Gabriele Freni and Valeria Puleo and Mauro De Marchis},
  series    = {EPiC Series in Engineering},
  volume    = {3},
  pages     = {1096--1103},
  year      = {2018},
  publisher = {EasyChair},
  bibsource = {EasyChair, https://easychair.org},
  issn      = {2516-2330},
  url       = {https://easychair.org/publications/paper/BC7f},
  doi       = {10.29007/6tgm}}

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