Impact of Temporal Population Distribution on Earthquake Loss Estimation: A Case Study on Sylhet, Bangladesh

Abstract

To estimate human loss in an earthquake-prone area, it is necessary to analyze the role played by the spatiotemporal distribution of the area's resident population. In order to evaluate earthquake impact, this article focuses on the spatiotemporal distribution of population and five scenario earthquakes that form the basis for loss estimation in the city of Sylhet, Bangladesh. Four temporal contexts (weekday, weekly holiday, the 30 days of Ramadan, and strike days) expand the more typical daytime and nighttime settings in which to examine hazard risk. The population distribution for every 2 hour interval in a day is developed for each type of day. A relationship between the occupancy classes and average space (persons per 100 m 2 ) is used to distribute people in each building regardless of building locations. A total daytime and nighttime population is obtained for each building and the estimated nighttime population is used to model the population for four temporal scenarios in a year based on different factors and weights. The resulting data are employed to estimate population loss for each of the temporal and earthquake scenarios. This study used building-specific human vulnerability curves developed by the Central American Probabilistic Risk Assessment (CAPRA) to obtain possible loss of life estimates. The results reveal that there is a high positive correlation between the spatiotemporal distribution of population and the potential number of casualties.

Assessing the impact of Syrian refugees on earthquake fatality estimations in southeast Turkey

“…Additionally, it is probable that the percentage of populations located outdoors is higher during working hours than during nighttime hours, especially in rural environments. These findings add to the growing volume of research stressing the importance of including temporal elements into natural-hazard studies (Chen et al, 2004;Ara, 2014;Aubrecht et al, 2012;Freire and Aubrecht, 2012;Guha-Sapir and Vos, 2011).…”

“…Accurately mapping population exposure is an essential part of the risk analysis process for environmental hazards (Chen et al, 2004;Freire and Aubrecht, 2012;Aubrecht et al, 2012). The presence of Syrian refugees in southeast Turkey complicates this process, especially as it pertains to datasets commonly used in earthquake fatality estimations.…”

“…Improved human exposure data impact several components of the risk analysis process, including loss estimation and disaster relief (Chen et al, 2004;Aubrecht et al, 2012;Guha-Sapir and Vos, 2011). Studies by Aubrecht et al (2012) and Ara (2014) have shown the paramount importance of incorporating temporal factors into population datasets.…”

“…Studies by Aubrecht et al (2012) and Ara (2014) have shown the paramount importance of incorporating temporal factors into population datasets. Despite these findings, most earthquake-related hazard studies do not account for temporal population changes and instead rely on census-based population estimates .…”

Multi-criteria Satisfaction Assessment of the Spatial Distribution of Urban Emergency Shelters Based on High-Precision Population Estimation

“…These studies indicated that the description and mapping of population distribution are basic and indispensable steps for disaster management, shelter selection, and emergency evacuations. Furthermore, daytime population distribution and density in urban areas are very different from the nighttime situation (Ara 2014). Freire (2010) used a dasymetric mapping approach to refine population distribution in Portugal.…”