Climate change impacts on rainfall intensity-duration-frequency curves in local scale catchments

Area of Science:

• Climatology
• Hydrology
• Environmental Science

Background:

• Climate change is increasing rainfall event intensity and frequency, challenging the construction of Intensity-Duration-Frequency (IDF) curves.
• Non-stationarity in extreme rainfall raises concerns about the reliability of traditional IDF curves for future climate projections and infrastructure planning.

Purpose of the Study:

• To investigate the validity of the Clausius-Clapeyron (CC) relationship in governing precipitation changes with temperature, as suggested by IPCC reports.
• To develop guidelines for adjusting IDF curves to account for future climate conditions.
• To assess the applicability of the generalized 7% precipitation increase per 1°C warming globally.

Main Methods:

• Calculated extreme precipitation changes and scaling factors for small urban catchments in Barranquilla, Colombia (tropical region) and Illinois, USA (temperate zone).
• Employed the bootstrapping method for statistical analysis.
• Conducted a comparative analysis between the tropical and temperate study sites.

Main Results:

• A sub-Clausius-Clapeyron (sub-CC) relationship was observed in Barranquilla, Colombia, indicating that the 7% rule is not universally applicable.
• The study site in Illinois, USA, demonstrated adherence to the Clausius-Clapeyron relationship.
• Significant variations in extreme precipitation scaling factors were found between the tropical and temperate regions.

Conclusions:

• The generalized 7% precipitation increase per 1°C warming is not universally applicable, particularly in tropical regions.
• Local parameter calculations are essential for accurate adjustments of IDF curves, rather than relying on generalized figures.
• The findings underscore the importance of region-specific analyses for climate change adaptation in hydrological infrastructure design.