This volume contains an overview of conventional and nonorthodox methods of representing and analyzing aspects of uncertainty in hydrology and water resources. Topics covered include: fractals, deterministic chaos, risk and reliability related criteria, fuzzy sets, pattern recognition, random fields, time series, stochastic modeling, outliers detection, nonparametric methods, information measures, and neural networks. Many new topics are discussed that make this book particularly valuable, and they include multifractals (applied to rain), a Bayesian relative information measure as a tool for analyzing the outputs of general circulation models, and a stochastic weather generator using atmospheric circulation patterns as a means to evaluate climate change.