A flood forecasting model on river Oise with the plugin Mascaret - PowerPoint PPT Presentation

A flood forecasting model on river Oise with the plugin Mascaret Reach Origny-Sainte-Benoite to Sempigny Authors : Patrick Chassé Contributors : Cédric Chabridier, Delphine Duval, Murièle Etangsale et Charles Sourdiaux (Flood forecasting service Oise-Aisne) TUC 2019 – 15 to 16 October 2019

Sempigny station

Plan of the présentation 1)Objectives of the project 2) Project approach 3) Construction of the model on the river Oise 4) Calibration and exploitation of the model 5) Conclusion 4 TUC 2019 – Cerfacs Toulouse

Reminder of objectives ● Check the feasibility of porting the existing model under Mascaret ● Take the test on one of the seven sections of the existing model: choice of the reach on the river Oise between Origny-Sainte-Benoite and Sempigny ● Implement the Mascaret plugin for Qgis 5 TUC 2019 – Cerfacs Toulouse

Project method ● From the existing model, including the position of cross sections ● Integrate the bathymetry of the profiles data ● Use the existing DEM (step 1m) ● Use the hydrological data of the HYDRO database (Origny-Sainte-Benoite, Condren, Sempigny, Serre, Ailette and Verse) ● Calibrate the model on the 2011 flood, and verify it on the 1993 and 1995 floods 6 TUC 2019 – Cerfacs Toulouse

Construction of the model on the river Oise ● Traces of the media profiles in the form of MapInfo tables (but the name of the profiles is not in attributes) ● Tracking profiles from images in pdf format (a bit heavy work phase) ● Retrieval of the profile file in Mascaret format for georeferencing from support profiles (fortran routines) ● Extract topo data from DEM on support profiles 7 TUC 2019 – Cerfacs Toulouse

Cross profile example 8 TUC 2019 – Cerfacs Toulouse

Construction of the model on the river Oise The model consists of : ● 5 branches ● 3 free extremities ● 175 cross profiles ● 1 basin (link between two branches separated by the lateral canal at Chatillon-sur-Oise) ● Two river-basin links 9 TUC 2019 – Cerfacs Toulouse

Hydraulic structure under the lateral canal 10 TUC 2019 – Cerfacs Toulouse

Link under the lateral canal 11 TUC 2019 – Cerfacs Toulouse

Calibration of the model Hydrological data available in the HYDRO database : ● Limnigraphs and hydrographs at Origny-Sainte- Benoite, Condren and Sempigny stations (2011, 1993, 1995, 2013 and 2016 floods) ● Hydrographs on the tributaries of the river Oise: the Serre, Ailette and Verse (same floods) ● Calibration flood : 2011 ● Validation floods : 1993, 1995, 2013 et 2016 12 TUC 2019 – Cerfacs Toulouse

Calibration of the model : flood 2011 Mascaret Hydrarive ● Results of calibration : K river = 18 and K floodplain = 8 ● Taking into account of diffuse inputs on the basis of the hydrograph of the river Serre 13 TUC 2019 – Cerfacs Toulouse

Calibration of the model : flood 2011 Mascaret Hydrarive 14 TUC 2019 – Cerfacs Toulouse

Calibration of the model : flood 2011 Mascaret Hydrarive 15 TUC 2019 – Cerfacs Toulouse

Validation flood : 1993 Mascaret Hydrarive 16 TUC 2019 – Cerfacs Toulouse

Validation flood : 1993 Mascaret Hydrarive 17 TUC 2019 – Cerfacs Toulouse

Conclusion ● The results of the calibration of the model with Mascaret are rather satisfactory (comparable in quality to the Hydra model) ● The porting objectives of the model under Mascaret have been achieved ● An occasion to test and improve the plugin Mascaret thanks to Artélia 18 Journées GASP Nancy 2019

Thank you for your attention Patrick Chassé Hydraulic modeling project manager +33 (0)3 44 92 60 62 patrick.chasse@cerema.fr