The lecture will start explaining why uncertainty assessments are important for hydrological modellling. Then commonly used uncertainty concepts and terminologies are explained and discussed – what is uncertainty and how can it be characterized? This will be followed by an introduction to a broad range of methods that can be used to estimate uncertainty, such as error propagation, Monte Carlo analysis, ensemble modelling and expert elicitation. Application of some of the uncertainty methods/tools will be illustrated by examples from practical cases, including a case study on observational and model predictive uncertainties in relation to distributed hydrological modelling. At last, it is discussed why water managers need to consider uncertainty when using hydrological models.

Key words:

Uncertainty, uncertainty methods, hydrological model, water resources management, data, parameter model structure.