Time-Series Study of Associations between Rates of People Affected by Disasters and the El Niño Southern Oscillation (ENSO) Cycle

• Main Authors: Holly Ching Yu Lam, Andy Haines, Glenn McGregor, Emily Ying Yang Chan, Shakoor Hajat
• Format: Article
• Language: English
• Published: MDPI AG 2019-08-01
• Series: International Journal of Environmental Research and Public Health
• Subjects: El Niño Southern Oscillation; natural disasters; number of people affected; El Niño; La Niña; Oceanic Niño Index (ONI)
• Online Access: https://www.mdpi.com/1660-4601/16/17/3146

The El Ni&#241;o Southern Oscillation (ENSO) is a major driver of climatic variability that can have far reaching consequences for public health globally. We explored whether global, regional and country-level rates of people affected by natural disasters (PAD) are linked to ENSO. Annual numbers of PAD between 1964&#8722;2017 recorded on the EM-DAT disaster database were combined with UN population data to create PAD rates. Time-series regression was used to assess de-trended associations between PAD and 2 ENSO indices: Oceanic Ni&#241;o Index (ONI) and multivariate El Ni&#241;o Index (MEI). Over 95% of PAD were caused by floods, droughts or storms, with over 75% of people affected by these three disasters residing in Asia. Globally, drought-related PAD rate increased sharply in El Ni&#241;o years (versus neutral years). Flood events were the disaster type most strongly associated with El Ni&#241;o regionally: in South Asia, flood-related PAD increased by 40.5% (95% CI 19.3% to 65.6%) for each boundary point increase in ONI (<i>p</i> = 0.002). India was found to be the country with the largest increase in flood-related PAD rates following an El Ni&#241;o event, with the Philippines experiencing the largest increase following La Ni&#241;a. Multivariate ENSO Index (MEI)-analyses showed consistent results. These findings can be used to inform disaster preparedness strategies.