Human activities change the atmospheric composition by increasing greenhouse gases. These changes have subsequently increased global temperatures, surface evaporation and atmospheric water holding capacity. As a result, climate change may increase the amount of water available for precipitation in the atmosphere as well as increase the probable maximum precipitation or expected extreme precipitation. Those changes in turn would increase the risk of climatic extremes that can cause flash floods and severe damages to human lives, society and infrastructure.
Focusing on different extreme distributions, two different modeling frameworks (stationary vs. non- stationary) were constructed in this research to capture the time-dependent location, scale and shape parameters of floods. The models indicate that increasing trends in monthly and seasonal floods could be explained by the influences of large-scale features such as the El Nino-Southern Oscilation, but changes in vegetation dynamics and in other atmospheric variables such as relative humidity cannot be excluded as influences.