Simulation of the hydrological functioning of a watershed: application to the design and management of a dam

Abstract

The hydrological model presented here is used to simulate the continuous operation of a dam, by generating flow data over a long period (1,000 years for example). This enables water volumes to be assessed as well as flood management. The generation of continuous real time information has two main advantages. Firstly, different dam management rules can be tested. Secondly, breakdowns can be analysed, after the event, by statistical processing of scenarios. The flood simulation is not a single event reduced to an artificial form: a series of floods, that build up behind the dam, are available to the designer to test the operation of the sluices and to carry out a statistical study of the flow leaving the dam. The method is based on two random rainfall generator models. Daily rainfall is generated continuously. The hourly rainfall generator model is activated when daily rainfall exceeds 20 mm. These models are linked to a model that converts rainfall into flow normally calculated on a daily basis but switching to an hourly basis during flooding. This paper presents the method and the various models used and also describes some examples.