Application of weather research and forecasting (WRF) model in evaluating depth-duration-frequency estimates under a future climate scenario

Point precipitation frequency estimates (PPFEs) are used in the design of stormwater drainage infrastructures. The PPFEs for 1-year to 1,000-year recurrence intervals with durations ranging from 5 min to 60 days are published in the National Oceanic and Atmospheric Administration (NOAA) Atlas 14. NOAA's published PPFEs are accepted as a reliable resource for the design of urban drainage infrastructures, yet they are based on the stationary climate assumption. However, future climate change may affect the distribution, frequency, and intensity of precipitation events. To evaluate the potential impacts of climate change on the stationary climate assumption, a weather research and forecasting (WRF) model was developed based on the medium climate change emission scenario. Then, the PPFEs were determined for 2010-2015, 2030-2035, 2050-2055, and 2070-2075 at six different locations in the state of Arizona. The comparison of the published and simulated PPFEs revealed a varying trend in depth and frequency values dependent on location and climate. Additionally, depth values were diminished for <3-h events at a majority of the stations.