Quels apports hydrologiques pour les modèles hydrauliques? Vers ...

545tributed lateral inflows were taken into account. Conversely, the point inflowoption required studying a large number of tributary combinations to identifythe optimal one.6 Conclusion550This article has investigated the coupling of lumped rainfall-runoff and hydraulicmodels. The motivation was to clarify the methods to be used fortel-00392240, version 1 - 5 Jun 2009555560generating inflows to the hydraulic model and to quantify the impact of differentoptions available when such tools are used to simulate flows on a riverreach. Two important questions were addressed: (1) How should RR modelsbe connected to hydraulic models? Should the connections be point or uniformlydistributed? (2) How many point connections should be introduced toreach an acceptable level of performance? These questions were investigatedby applying the GR4J lumped RR model and the linearised diffusive waverouting model on a 95-km reach of the Illinois River within the DMIP 2 studyarea. Coupled models were calibrated with two options in lateral injections(point inflows only or point and uniformly distributed inflows combined) andsix levels of injection resolution (one to six tributaries).The main findings of this study can be summarised as follows:565• Uniformly distributed inflows lead to more robust and stable coupled models.A similar level of performance can be reached with models using point inflowsonly, but less stable performance and parameters between sub-periodswere observed, with increased risks of undesired parameter compensations.• The identification of the optimal number of tributaries is easier when a26