Natural Calamity Deaths in Nepal: Analysis of the 2021 National Population and Housing Census

Abstract

Background: Nepal is one of the most disaster-prone countries in South Asia due to its rugged terrain, monsoon- driven precipitation, and active seismicity. However, evidence on the demographic and geographic patterns of mortality associated with natural calamities remains limited. This study examined natural-calamity mortality in Nepal using nationally representative census data, with particular emphasis on differences by age, sex, wealth, residence, province, and district-level geographic exposure. Method: Data on household-reported natural-calamity deaths were obtained from the 2021 National Population and Housing Census (NPHC). Weighted individual records were used to construct sex-, age-, wealth quintile-, and residence- specific exposure populations. A negative binomial mixed-effects regression model with a log-population offset was fitted to estimate incidence rate ratios, with sex, age group, wealth quintile, place of residence, and province included as fixed- effect predictors. A district-level random intercept was incorporated to account for geographic clustering in natural-hazard exposure. Results: Among 198,463 deaths recorded in the census, 9,595 (4.83%) were attributed to natural calamities, correspond- ing to a national mortality rate of 32.9 per 100,000 population. Madhesh Province recorded the highest mortality rate (55.8 per 100,000) and the highest proportion of all deaths attributable to natural calamities (10%). Mortality followed a J-shaped age pattern, with the lowest risk among working-age adults and the highest among individuals aged 75 years and above. Mortality was significantly higher among males than females and among urban than rural residents. Only in- dividuals in the wealthiest households experienced significantly lower mortality than those in the poorest households. No province-level differences remained statistically significant after accounting for geographic clustering below the provincial level. Substantial variation persisted across districts, with the highest-risk districts distributed across several provinces. Conclusion: Natural-calamity mortality in Nepal is shaped not only by age, sex, wealth, and place of residence but also, importantly, by localized district-level exposure. The absence of significant province-level differences after accounting for district clustering suggests that disaster risk varies considerably within provinces. Disaster-risk-reduction investments and early-warning systems should therefore be targeted at the district level, with evacuation and preparedness strategies tailored to vulnerable age groups and residential settings.