Artificial neural networks (ANN) are a novel approximation method for compl
ex systems especially useful when the well-known statistical methods are no
t efficient. The multilayer perceptrons have been mainly used for hydrologi
cal forecasting over the last years. However, the connectionist theory and
language are not much known to the hydrologist communauty. This paper aims
to make up this gap. The ANN architectures and learning rules are presented
to allow the best choice of their application. Stochastic methods and the
neural network approach are compared in terms of methodology steps in, the
context of hydrological forecasting. Recent applications in hydrology are d
ocumented and discussed in the conclusion.