Intensity-duration-frequency approach for risk assessment of air pollution events

Area of Science:

• Environmental Science
• Atmospheric Science
• Risk Assessment

Background:

• Extreme environmental events pose significant risks.
• Intensity-Duration-Frequency (IDF) curves are valuable for risk assessment.
• Assessing extreme air pollution events requires robust methodologies.

Purpose of the Study:

• To propose and apply an IDF approach for evaluating extreme air pollution risk.
• To analyze the probabilistic behavior of air pollution index (API) using Generalized Extreme Value (GEV) distribution.
• To develop IDF curves for estimating extreme pollution intensities for Klang city, Malaysia.

Main Methods:

• Utilized hourly air pollution index (API) data from Klang city, Malaysia (1997-2016).
• Applied block maxima approach considering monsoon seasons for annual data.
• Modeled extreme API values using Generalized Extreme Value (GEV) distribution to construct IDF curves.

Main Results:

• Developed IDF curves correlating pollution intensity, duration, and return periods.
• Demonstrated a positive relationship between pollution intensity magnitude and increasing return periods.
• Confirmed that high-intensity pollution events are less frequent than low-intensity events.

Conclusions:

• IDF curves effectively estimate expected extreme air pollution intensities.
• The developed approach provides a strong foundation for decision-makers in environmental risk management.
• This methodology aids in understanding and mitigating the risks associated with severe air pollution episodes.