Implementing Hydrologic Design to Address Non-Stationary Climate
Abstract
Precipitation-based intensity-duration-frequency (PREC-IDF) curves estimated using historical observations are the standard approach to characterize extreme flood events. For flooding associated with snowmelt or rain-on-snow (ROS), however, the standard PREC-IDF method can significantly underestimate flood peaks, leading to the potential under-design of hydraulic structures. Using stationary PREC-IDF curves further worsens the problem because of climate change when historical observations no longer represent the future climate condition. To overcome the long-standing issue and enhance the characterization of nonstationary flood events for engineers, we propose the Next-Generation Intensity-Duration-Frequency (NG-IDF) curves which explicitly account for the mechanisms of extreme water available for runoff including rainfall, snowmelt, and ROS under a nonstationary climate. We generate the historical NG-IDF curves at 1/16-degree (~ 6km) resolution over the Conterminous United States (CONUS) for nine land cover types (open land, evergreen forest, deciduous forest, mixed forest, crop, grass, pasture, shrub, and wetland), which is consistent with the National Land Cover Database (NLCD) and the Technical Release 55 (TR-55) single event hydrologic model design guidelines. We employ the Intermediate Complexity Atmospheric Research (ICAR) model to generate NG-IDF curves under future climate conditions. To provide increased flexibility and facilitate technology transfer, we developed a web-based tool to generate local NG-IDF curves based on user-specified location and vegetation canopy characteristics.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2022
- Bibcode:
- 2022AGUFM.H41A..05W