Tsunami mortality estimates and vulnerability mapping in Aceh, Indonesia

We aimed to quantify tsunami mortality and compare approaches to mortality assessment in the emergency context in Aceh, Indonesia, where the impact of the 2004 tsunami was greatest.

Mortality was estimated using geographic information systems-based vulnerability models and demographic methods from surveys of tsunami-displaced populations.

Tsunami mortality in Aceh as estimated by demographic models was 131066 and was similar to official figures of 128063; however, it was a conservative estimate of actual mortality and is substantially less than official estimates of 168561 presumed dead, which included those classified as missing. Tsunami impact was greatest in the district of Aceh Jaya, where an estimated 27.0% (n=23862) of the population perished; Aceh Besar and Banda Aceh were also severely affected, with mortality at 21.0% (n = 61 650) and 11.5% (n = 25 903), respectively. Mortality was estimated at 23.7% for the population at risk and 5.6% overall.

Mortality estimates were derived using methodologies that can be applied in future disasters when predisaster demographic data are not available. Models could be useful in the early stages of disaster response by facilitating geographic targeting and management of humanitarian assistance.