Final Presentation UNSA, Nice HydroEurope 05 th March, 2010

What are or what should be the reasonable criteria for the Var model calibration (MIKE 11 & MIKE SHE) ? Team Members Claire Elodie Freda YiGopi Sandor Sun-Ah

 MODEL CALIBRATION IN GENERAL  MIKE SHE  MIKE 11  RECOMMENDATIONS & CONCLUSION  HYDROEUROPE

 Before Calibration *Details of the model area *Input data *Model selection *Sensitivity analysis  During calibration *Physical meaning of parameters After calibration *Compare with validation data

Spatial discretisation: 300 m grid resolution Not able to consider sharp changes in topography Discharge is underestimated Simulated discharge Q= 100 cu.m/sec Coupling would help to overcome this problem

 Simulation Period  Selection ( 1 or 3 days )  Influence – before & after 3 days result1 day result

 Data Accuracy & Reliability  Height is known but the discharge value is estimated from height

 Do we need to calibrate everytime?

MIKE 11 - Model build up  Built only for the Lower Var River  Provided data i.e. network, x-sects  Upstream boundary – Q at Var and Esteron confluence from MIKE SHE/ MIKE 11 coupled model of entire Var catchment.  Downstream – Sea level  Strickler, M = 30 m 1/3 /s (default)  Weir coeff same for all ≈ (provided in river network file)

Rougness decreases, discharge downstream increasesRougness decreases, Max water level increasesWeir coeff decreases, Max Water level increases Weir 8 Weir 7

No reliable observed discharge values – no calibration done with discharge. Max water level - discharge relation only established for the low usual discharge values of stage Calibration done using maximum water levels over river length. After Calibration, Strickler, M = 24 Weir coeff =

Strickler = 24. Accept value - within range for river beds with gravel and boulders similar to sediment present This value is not due to only grain size of sediment according to Strickler’s equation. It also contains: Energy loss due to turbulence effects Friction due to river bed geometry and banks Energy loss due to vegetation Considered uniform along entire length of river – not reality (sediment and boulders differ along river) Also not even along a cross section – ie the river, sediment deposits, sand bars and banks

 Honma weir equation with an original, C ≈ =c √2g and calibrated coefficient C = c √2g = 2  Calibrated value of C= 2 (has a factor of √2g)  Without the factor, c ≈ for all weirs. Usu.range is 0.5 – 0.7 but is acceptable – higher energy loss due to power station.  Not realistic for all weirs to have similar coeffs. Weir 6 Weir 7 Weir 5 Weir 4

 Sediment transport not simulated  Flooding over the river banks not accounted for by model  Weirs 10 and 16 are currently submerged  Weirs 2 and 3 washed away during flood of 1994 but existed during the flood, so also had a effect on the flood routing  Cross sections are always changing. Flood was in sections measured in 2001 and we are designing for the future. Model questionable???  Upstream boundary is from a model, with uncertainty  Downstream boundary is also not very certain (sea level???)  No validation data available

 Set up more data collection/metrological stations in entire catchment i.e. rainfall  Use updated data  Observations during flood  Cross sections  Weir characteristics  Appropriate resolutions give better results according to study objectives  During calibration, do not forget to think about the physical processes and significance of parameters.  Including the flooded zone (e.g. MIKE FLOOD) is recommended to have better model calibration i.e. simulate water that flows over the river banks.  Seek the opinion of the experts and model for a wider range of possible events

Team AQUAHOLIX

Happy B’day Kate !!!

Thanks for your attention !!! 감사합니다 köszönöm a figyelmet Danke Gracias Merci Gràcies धन्यवाद Спасибо 謝謝 ありがとう Bedankt Хвала Cảm ơn Mwanyala nnabiAsante sana