Disasters Never Arrive Alone

Anak Krakatau has once again demonstrated that disasters rarely stop at their primary source. The eruptions occurring since early September have produced more than just incandescent material and volcanic ash. The ash has spread far from the crater, disrupting flight operations at six airports, including Soekarno-Hatta, and affecting hundreds of flights. Schools have closed in several affected areas, fishing activities have been restricted, and citizen mobility has been disrupted.

It is the volcano that erupts, but it is the system that is disrupted.

This distinction is vital because our understanding of disasters often remains limited to their immediate source. Volcanoes are treated as matters of volcanology; earthquakes as seismology; forest fires as forestry issues. However, when a disaster occurs, its impact does not recognise the sectoral divisions found within bureaucratic structures.

Cascading Risk

In disaster studies, this phenomenon is known as cascading risk or systemic risk. The essence is simple: a hazard does not only cause direct damage but can also trigger secondary disruptions that move through networks of infrastructure, economy, health, mobility, and social life.

A volcanic eruption, for instance, can disrupt aviation. Aviation disruptions hit the mobility of people and goods. Access closures can hinder logistics, tourism, economic activity, and even the distribution of basic services. While the hazard radius of a volcano can be mapped, the radius of systemic disruption is not as straightforward. Indonesia has witnessed similar patterns many times.

The 2018 Palu disaster should make this logic familiar. The earthquake did not just shake buildings; in a single sequence, tsunamis, liquefaction, and landslides formed a far more complex disaster. The ultimate extent of the damage was determined not only by the strength of the initial tremor but also by the relationship between the hazard, infrastructure, spatial planning, and community vulnerability.

Earthquakes may collapse houses, but the subsequent consequences do not end with buildings. Residents move to evacuation centres, where needs for sanitation, health, security, child protection, and aid distribution emerge. In East Nusa Tenggara, a refugee under the age of 15 was reported as a victim of sexual violence amidst the evacuation situation. The government subsequently provided assistance and prepared special tents for women and children. This case illustrates a rarely discussed paradox: an individual can be saved from one risk only to encounter another.

Evacuation does indeed reduce the likelihood of being crushed by buildings. However, if evacuation centres are not designed with adequate security, lighting, sanitation, protection for vulnerable groups, and supervision, the safety gained from evacuation can be followed by new vulnerabilities. Forest and land fires provide an even clearer example. Fire may start in one area, but smoke moves with the wind. In early September, Serian in Sarawak even declared a state of emergency when the air pollution index reached dangerous levels. Schools had to close in parts of Malaysia. A fire may be contained within one regency, but its consequences can become a regional issue.

Fragmented Bureaucracy

This is where the real problem arises. The modern state is built through the division of authority. There are agencies that monitor volcanoes, agencies that read the weather, agencies that manage transport, health, search and rescue, the environment, social protection, and local governments.

This division is necessary. The problem is that risk does not operate in the same way. Disasters move horizontally while bureaucracy works vertically. We may have agencies that are excellent at reading volcanic activity, but that knowledge only becomes protection if it is rapidly translated into decisions regarding aviation, schools, health, traffic, and public communication. We may know hotspots with high precision, but that information is only valuable if law enforcement, land management, health, education, and environmental diplomacy move before smoke turns into a transboundary crisis.

Therefore, Indonesia’s problem may not be a lack of institutions. We actually possess many institutions that understand the individual components of a disaster. What is more difficult is ensuring all those parts read the same risk chain. Within a framework of systemic risk, connectivity is what matters. A disruption in health can affect the economy. Infrastructure damage hinders food distribution. Communication failure can exacerbate the response. Conversely, a single decision in one sector can either mitigate or create risk for another.

Our policy language is still often trapped in a single question: has the disaster been handled? The question that should be asked is: after the first disruption occurs, what is likely to fall next?

Testing the Chain of Failure

This is where Indonesia needs a change in how it conducts disaster simulations. So far, exercises are often built around a single main scenario: an earthquake occurs, a tsunami arrives, a volcano erupts, or a fire spreads. Such scenarios remain important, but they are not enough. What needs to be tested is the chain of failure.

Imagine a major eruption. Airports are closed. Several roads are disrupted. Evacuation centres swell. Hospitals begin to reach capacity. Medicine distribution is delayed. Communication signals weaken. The power supply in one region is disrupted. At what point does the system begin to lose its ability to function? Such a question requires a kind of cascading-risk stress test in disaster-prone areas—not to perfectly predict what will happen, but to find the weak points before a crisis tests them.