Modelling Individual Evacuation Decisions during Natural Disasters: A Case Study of Volcanic Crisis in Merapi, Indonesia

Jumadi Jumadi,Steve Carver,Alison Heppenstall,Vern Manville,Nick Malleson,Duncan Quincey

doi:10.3390/geosciences8060196

Jumadi Jumadi, Steve Carver + Show 4 more

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https://doi.org/10.3390/geosciences8060196

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Abstract

As the size of human populations increases, so does the severity of the impacts of natural disasters. This is partly because more people are now occupying areas which are susceptible to hazardous natural events, hence, evacuation is needed when such events occur. Evacuation can be the most important action to minimise the impact of any disaster, but in many cases there are always people who are reluctant to leave. This paper describes an agent-based model (ABM) of evacuation decisions, focusing on the emergence of reluctant people in times of crisis and using Merapi, Indonesia as a case study. The individual evacuation decision model is influenced by several factors formulated from a literature review and survey. We categorised the factors influencing evacuation decisions into two opposing forces, namely, the driving factors to leave (evacuate) versus those to stay, to formulate the model. The evacuation decision (to stay/leave) of an agent is based on an evaluation of the strength of these driving factors using threshold-based rules. This ABM was utilised with a synthetic population from census microdata, in which everyone is characterised by the decision rule. Three scenarios with varying parameters are examined to calibrate the model. Validations were conducted using a retrodictive approach by performing spatial and temporal comparisons between the outputs of simulation and the real data. We present the results of the simulations and discuss the outcomes to conclude with the most plausible scenario.

Highlights

Geophysical events, such as earthquakes, volcanic eruptions, landslides, and flooding, have been occurring on the planet long before the advent of humans, but these events are transformed into natural disasters when they threaten human life [1]
The occurrence of natural disasters has increased over the last decades in line with the increase in the human population, because more people are occupying those areas which are susceptible to such events [2]
Among the various natural hazards, volcanic eruptions pose a significant threat to Indonesia, as it is located within the “Ring of

Summary

Introduction

Geophysical events, such as earthquakes, volcanic eruptions, landslides, and flooding, have been occurring on the planet long before the advent of humans, but these events are transformed into natural disasters when they threaten human life [1]. Developing a model can be intricate and needs an appropriate approach. It is a complex social process, resulting from many interrelating physical and social factors. Studies have identified that evacuation decisions are influenced by several factors [23,24,25] including: (1) risk communication and warning; (2) perception of risk; (3) community and social network influence; and (4) disaster likelihood, environmental cues, and natural signals. Risk perception is responsible for influencing people’s decisions on when they should evacuate, and when they should return home during a crisis [27]. Another study by Botzen et al [30] has stated that some demographic aspects, namely location, experience, knowledge, and socioeconomic status, contribute to the perception of the population toward risk. The perceptions of people who live on and around the volcano commonly vary, and this affects the warning-response outcome [31,32]

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