A Study of Flood Evacuation Route Selection in Kampong Settlements in Indonesia

Emergency evacuation is an important disaster response. Recent frequent occurrences of natural and man-made disasters necessitate effective evacuation planning. It includes factors such as road network properties, street geometry, road risk and environmental information. Such plans are difficult to implement because of the complex psychological responses of affected people during an emergency. For example, in flood disaster preparedness, the responsiveness and resilience of the community at risk is critical. However, little is known about how residents of informal settlements negotiate their surroundings during evacuation.

Recently, Mr. Irsyad Adhi Waskita Hutama (PhD student) and Professor Hitoshi Nakamura from Shibaura Institute of Technology, Japan, analyzed the dynamic interaction between human characteristics, road risk elements, and road network configuration in constructing evacuation route choices during floods. The study was conducted in Terban and Bener, which are two urban river kampongs (villages) in Yogyakarta, Indonesia. Their findings were published in International Journal of Disaster Risk Reduction.

Prof. Nakamura reveals his motivation behind the research: “Kampongs on riverbanks in Indonesian cities have grown spontaneously. Their residents typically include low-income and marginalized people who lack disaster prevention infrastructure. I am interested in how such communities can undertake disaster risk management and future disaster mitigation. A study of evacuation measures in riverside kampongs will show reliable life-saving actions in response to floods, earthquakes and other disasters.

The researchers used a mixed method approach. First, they collected extensive data on road risk factors through videotaped walking evacuation simulations. Walking interviews were then conducted to obtain exploratory information about individual capacity and decision-making. Finally, the researchers performed a computational road network analysis using the space syntactic model. The results of these analyzes were combined to paint the overall picture.

Their findings suggest that coastal kampong residents choose evacuation routes based on their individual capacity and the safety effectiveness of the path design. Many of them rely on the perception of safety instead of following spatial logic. Consequently, their evacuation route decisions may be compromised. In addition, the walking interview revealed that males had higher spatial legibility and road safety perception than females in both cases.

In addition, the researchers compared the results of the space syntax with the walking evacuation simulation. Individual evacuation route choice was found to be highly correlated with “normalized angular choice at local radii”.

This means that the majority of residents prefer to take the straightest route – with the least angular deviation – to reach the assembly points. Furthermore, in agreement with personal interviews, residents have different abilities to follow the most direct evacuation route. In particular, physical capacity, gender and age influenced people’s decisions in negotiating risky elements of the road and adjusting to the safest journey.

Prof. Nakamura points out the long-term implications of the research. “Our study attempts to shift the research tradition on disaster studies that focus on the morphological approach on the one hand and the human-centered approach on the other.” His findings show a political view that includes disaster prevention routines matching the socio-spatial profiles of marginalized people in the kampong. Improvement includes not only structural measures such as human-sensitive urban design, legibility of evacuation routes through signs and provision of evacuation infrastructure, but also community preparedness. These measures should be included in kampong upgrading and slum alleviation policies aimed at achieving the SDGs.”

Overall, the study highlights the use of mixed methods approaches and highlights the need to consider a human-centered perspective in effective flood emergency evacuation planning for informal riverside settlements.