A River Network?Based Hierarchical Model for Deriving Flood Frequency Distributions and Its Application to the Upper Yangtze Basin

In flood frequency analysis, expanding the additional information with hydrological reasoning beyond local at-site samples can be very useful for improving accuracy of distribution (FFD) estimation as well reflecting a better understanding characteristics. this study, river network-based hierarchical model is developed to estimate FFDs in Upper Yangtze basin by making full use both dependence within network and reservoir regulation. Under model, covariate analysis based on generalized additive location, scale shape performed obtain conditional interested variable given its upstream variables index quantifying regulation; then, FFD derived combining probability variables. The application indicates that proposed suggests satisfactory performance estimation. It also found regulation, especially Three Gorges Reservoir, great significance reducing magnitude basin. Compared conventional method directly fits assumed theoretical distributions samples, incorporating exhibits an advantage capturing effect regulation floods uncertainty quantile