Analysis of potential impacts of climate change on intensity–duration–frequency (IDF) relationships for six regions in the United States

Abstract

Potential changes in climate are expected to lead to future changes in the characteristics of precipitation events, including extreme rainfall intensity in most regions. In order for government agencies and design engineers to incorporate these trends and future changes into assessment and design processes, tools for planning and design should be capable of considering nonstationary climate conditions. In this work, potential changes are investigated in intensity-duration-frequency (IDF) curves, which are often used for assessment of extreme rainfall events, using historic data and future climate projections. An approach is proposed for calculating IDF curves that incorporates projected changes in rainfall intensity at a range of locations in the United States. The results elucidate strong regional patterns in projected changes in rainfall intensity, which are influenced by the rainfall characteristics of the region. Therefore, impacts of climate change on extreme hydrologic events will be highly regional and thus such assessments should be performed for specific project locations.

Framework for Incorporating Downscaled Climate Output into Existing Engineering Methods: Application to Precipitation Frequency Curves

“…The change factor approach and the bias-correction approach have been employed to adjust statistical metrics. The change factor, or delta change, approach adjusts an observed statistic (usually at the point scale) to a future date using a ratio or percentage that is calculated from the gridded, climate model output (Forsee and Ahmad 2011;Zhu 2012). Bias correction modifies the future, gridded value from the downscaled climate model based on the difference between the observed statistics (point scale) and past model simulation statistics (grid scale) or hindcast simulation statistics (grid-scale) (Arnbjerg-Nielsen et al 2013; Boé et al 2007;Chen et al 2015;Wilks and Wilby 1999;Wood et al 2000).…”

“…However, it has been hypothesized that if the engineer is only concerned with designing for extremes, it may be more manageable to avoid downscaling to a continuous time series, and instead adjust empirical quantiles through mapping functions (Hassanzadeh et al 2013). A simple method that has been introduced in the engineering literature involves directly adjusting historical rainfall depths at the point scale, for a given return period and duration, based on the expected change from historical to future conditions at the grid scale (Zhu et al 2012;Forsee and Ahmad 2011). Areal reduction factors have been employed to adjust the station scale rainfall, as reported by Zhu et al (2012), and summarized here in Equation 2.…”

“…A simple method that has been introduced in the engineering literature involves directly adjusting historical rainfall depths at the point scale, for a given return period and duration, based on the expected change from historical to future conditions at the grid scale (Zhu et al 2012;Forsee and Ahmad 2011). Areal reduction factors have been employed to adjust the station scale rainfall, as reported by Zhu et al (2012), and summarized here in Equation 2.…”

“…Arnbjerg-Nielsen et al 2013;Forsee and Ahmad 2011). These climateinformed local-scale models have also been used to update intensity-duration-frequency curves used in design of infrastructure affected by rainfall (Chandra et al 2015;Cheng and AghaKouchak 2014;Forsee and Ahmad 2011;Zhu 2012;Kuo et al 2015;Hassanzadeh et al 2013;Mirhosseini et al 2013).…”

Comparação de duas metodologias de obtenção da equação de chuvas intensas para a cidade de Caraguatatuba (SP)

“…De acordo com Zhu et al (2012), as curvas de intensidade, duração e frequência (IDF) são uma ferramenta probabilística que já provou ser muito útil no planejamento e no projeto do manejo de recursos hídricos e na engenharia. Os autores ainda salientam que elas são capazes de fornecer uma avaliação das características dos extremos de precipitação.…”