The objective of flood frequency analysis (FFA) is to associate flood intensity with a probability of exceedance.Many methods are currently Dryer Motor Pulley employed for this, ranging from statistical distribution fitting to simulation approaches.In many cases the site of interest is actually ungauged, and a regionalisation scheme has to be associated with the FFA method, leading to a multiplication of the number of possible methods available.This paper presents the results of a wide-range comparison of FFA methods from statistical and simulation families associated with different regionalisation schemes based on regression, or spatial or physical proximity.
The methods are applied to a set of 1535 French catchments, and a k-fold cross-validation procedure is VIT.C 500MG MIXED FRUIT used to consider the ungauged configuration.The results suggest that FFA from the statistical family largely relies on the regionalisation step, whereas the simulation-based method is more stable regarding regionalisation.This conclusion emphasises the difficulty of the regionalisation process.The results are also contrasted depending on the type of climate: the Mediterranean catchments tend to aggravate the differences between the methods.