La surveillance du risque hydrologique pour la gestion d'un reservoir hydrique

This master thesis presents a tool intended to assess the hydrological risk of malfunction of a hydrologic system. It was meant as an illustration and a feasibility study of a new water management approach currently in development at Ecole Polytechnique de Montreal. This approach intends to introduce the concept of 'risk index' in the panoply of tools available to reservoir operators. The knowledge of the risk index allows the manager to act pre-emptively when his system is at risk and can give him sufficient confidence to take the system outside the normal boundaries of operation and maximize his power output when the risk is low.; This tool proposes to calculate the return period of reservoir malfunctions (non-compliance to normal operating procedures, overflow, etc.). This represents a reverse problem as we are looking to find the cause from the consequence. This goal is achieved through the combined application of the unit hydrograph theory, Horton's infiltration model, and the continuity equation as well as a numerical shooting method. This allows finding the rain that will cause the malfunction and IDF curves permit us to assign it a return period. The calculation takes into account the instantaneous state of the system (saturation of the soil, water levels, state of the spillways) as well as antecedent conditions such as rains. Furthermore the presented tool introduces the premise of a short term prevision of the risk index through a 24 hour prediction.; The calculation tool was put in application on reservoir Kenogami during the spring/summer seasons of 199 and 1996. It illustrates the high state of risk associated with the reservoir at these periods.