An Efficient Statistical Approach to Develop Intensity-Duration-Frequency Curves for Precipitation and Runoff under...

Area of Science:

• Hydrology and Climate Science
• Environmental Engineering
• Urban Planning

Background:

• Climate change impacts water management infrastructure, especially urban drainage systems.
• Current stormwater design standards often rely on precipitation intensity-duration-frequency (IDF) curves.
• General Circulation Models (GCMs) project temperature increases but have limited skill in predicting extreme precipitation events.

Purpose of the Study:

• To develop an efficient and automatable approach for estimating future IDF curves.
• To provide a method consistent with existing US IDF curves and GCM model-agnostic.
• To assess the potential changes in storage volume requirements for stormwater management practices by 2065.

Main Methods:

• Utilized statistically downscaled GCM output for future climate projections.
• Employed equidistant quantile mapping to address model biases and adjust extreme value fits.
• Estimated future IDF curves across the United States using annual maxima data.

Main Results:

• Developed a method to estimate future IDF curves directly applicable to stormwater regulations.
• Linked IDF-derived design storms to a rainfall-runoff model.
• Evaluated potential changes in storage volume requirements for capture-based stormwater management practices.

Conclusions:

• The proposed method offers a straightforward approach for developing future climate scenarios for stormwater infrastructure risk assessment.
• The methodology is efficient, automatable, and adaptable to various GCM projections.
• Findings will inform the adaptation of urban drainage systems to projected climate change impacts.