Thinking of the disastrous aftermath of floods, I would consider whether the incidence of floods get worse or not, especially under anthropogenic influence environment. Milly et al., 2002 pointed out that there is an increasing frequency of great floods mostly in northern high latitudes, which considered under climate change from anthropogenic radiative effects. They even made a projection of extratropical flood frequency using observed data and several models. Figure1 shows clearly about different start points of trends with statistical significance, and all trends from various models turn to be obvious at a certain year. But because of incomplete consideration of other possible forcing such as various land-use, some errors of models and other factors, the conclusion is tentative.
(Normalized trends greater than 1 imply significance with respect to this measure.
Bold curves: historical records; Light curves: continuing operation)
Hirabayashi et al., 2008 uses MIROC model to estimate the change of floods under global warming situation. There seems to be a link between flood frequency and river annual discharge. Increasing frequency of river floods accompanied by increasing annual discharge, but can not be inferred in reverse.
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