Every dry season, forest and land fires return to parts of Sumatra, spreading smoke and putting pressure on firefighting teams. As part of Indonesia's wider wildfire problem. these recurring fires are driven by vulnerable landscapes, land-use practices and prolonged dry weather.
But why do the fires keep returning? In areas with drained peatlands, fires can smoulder underground even after visible flames disappear. In South Sumatra, the scale of the challenge was evident in 2026, with 1,723 fire incidents and approximately 1,926 hectares of burned land recorded by August 23. Understanding why these fires recur is essential to breaking the cycle.
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| a meeting at the Forward Command Post of the Riau Province Forest and Land Fire Task Force Photo by https://setkab.go.id/ |
1. Sumatra's Landscapes Can Become Vulnerable to Repeated Fires
Sumatra contains tropical rainforests, peat swamp forests, wetlands, agricultural landscapes and areas that have been converted for plantations or other uses.
These environments do not respond to fire in the same way. Some ecosystems can experience occasional natural or human-caused fires, while humid forests and peatlands may suffer serious damage when burning occurs under unsuitable conditions.
The risk increases when land is disturbed and vegetation becomes drier. Forest clearance, drainage, degraded vegetation and prolonged dry weather can combine to make ignition more likely and fire suppression more difficult.
This does not mean that every part of Sumatra faces the same risk. Fire patterns vary across provinces and even between neighboring landscapes.
Riau, Jambi and South Sumatra are particularly relevant to discussions of peatland fires, land management and recurring haze. However, the reasons for a specific fire must be assessed locally rather than assumed from its location alone.
The important question is not simply whether a landscape has burned before. It is whether the conditions that allowed the fire to happen have changed.
2. Peatlands Can Keep Fires Burning Beneath the Surface
Peatlands are among the most important parts of Sumatra's recurring fire problem.
Peat forms over long periods as partially decomposed plant material accumulates in waterlogged conditions. When peat remains wet, it stores large amounts of organic carbon and supports distinctive ecosystems.
But when peatlands are drained, their water levels can fall. The exposed material becomes more vulnerable to drying and ignition, especially during prolonged periods without sufficient rainfall.
Unlike a fire that spreads only through surface vegetation, a peat fire can burn underground. Flames may disappear from view while heat and smouldering combustion remain within the peat layer.
This creates a serious challenge for firefighters.
A location that appears extinguished may still contain burning material capable of reigniting or spreading when conditions become favorable. Effective suppression can require extensive wetting, cooling, monitoring and verification.
Indonesia's Ministry of Forestry has repeatedly emphasized the need for continued ground operations and cooling in peatland areas because underground embers can persist after surface flames are gone.
The lesson is straightforward: putting out visible flames is not always the same as extinguishing a peat fire completely.
3. Drainage Can Make the Fire Problem Harder to Solve
Peatland drainage is important because it can change the conditions that once kept the ecosystem wet.
Canals built to lower water levels may make land more accessible for certain agricultural or plantation activities. However, drainage can also dry peat, increase its exposure to oxygen and make it more vulnerable to burning.
Once a peatland has been drained and degraded, the effects can extend beyond a single fire season.
The landscape may remain vulnerable during future dry periods, particularly when water levels fall further. If the same area is repeatedly disturbed, its ability to recover may be weakened.
This creates a difficult management problem. Fire suppression addresses an active emergency, but it does not automatically restore the hydrological conditions that made the peatland resistant to burning.
Long-term prevention therefore requires more than emergency crews. It can involve maintaining appropriate water levels, restoring damaged peatlands, managing canals and reducing activities that leave peat excessively dry.
Peatland restoration is not a quick fix, and results depend on local conditions. Nevertheless, addressing the underlying water problem is an important part of reducing future fire risk.
4. Land Clearing Can Introduce New Sources of Ignition
Fire does not begin simply because a landscape is dry. An ignition source is also needed.
Across Indonesia, land clearing and the use of fire have been identified by authorities as recurring concerns in forest and land fire prevention. Fires may start through deliberate burning, accidental ignition, escaped land-clearing fires or other human activities.
In Sumatra, where agricultural land, plantations, forests and peatlands can occur near one another, a fire that begins in one location may spread into surrounding vegetation under dry conditions.
However, it is important to distinguish between a general risk and responsibility for an individual incident.
A fire occurring near a plantation does not, by itself, prove that the plantation operator started it. Determining responsibility requires evidence about the ignition point, land control, activities taking place and the circumstances of the incident.
The same principle applies to smallholders, communities and other land users.
Effective prevention requires consistent rules, education, monitoring and enforcement. Where investigations establish that an individual or company has violated the law, accountability should follow the evidence.
Without reliable investigation and enforcement, repeated burning can become difficult to prevent, regardless of whether the ignition was intentional or accidental.
5. Why Fires Return During Dry Weather
Rainfall is one of the most important factors influencing fire risk.
When vegetation and peat retain sufficient moisture, ignition and fire spread may be more difficult. During a prolonged dry period, however, moisture levels can decline, allowing fires to start more easily and spread more rapidly.
The effect can be particularly severe in landscapes that have already been drained or degraded.
El Niño can contribute to this risk by changing rainfall patterns across parts of Indonesia. Its effects vary by event and location, but drier conditions can increase the vulnerability of fire-prone landscapes.
El Niño should not be treated as the sole cause of Sumatra's fires. It does not explain who or what ignited a particular fire, nor does it explain every difference in fire activity between provinces.
Instead, climate conditions interact with local land management and available ignition sources.
A prolonged dry period can turn a vulnerable landscape into a more dangerous one. When the underlying conditions remain unchanged, another dry season can recreate the conditions for another fire.
For a wider explanation of the relationship between climate and fire risk, see El Niño and Indonesia's Wildfire Risk.
6. Why One Fire Season Can Prepare the Ground for Another
Repeated fires can create a self-reinforcing cycle, particularly where land has already been disturbed.
When a fire damages vegetation, it can reduce the protective cover over the soil and alter the structure of the ecosystem. If peat burns, the loss may include carbon-rich material that took a very long time to accumulate.
Recovery depends on the severity of the damage, the ecosystem involved, water conditions and whether further disturbance occurs.
Where drainage and land conversion continue, the landscape may remain vulnerable even after vegetation begins to grow again. Another prolonged dry period can then expose the same area to renewed fire risk.
The pattern is not inevitable, and not every burned area will burn again. But repeated fires become harder to prevent when the conditions that supported previous fires remain in place.
How the Cycle Repeats
The recurring fire problem can be understood as a sequence of connected conditions.
Land disturbance may reduce vegetation cover or lower peat water levels. The resulting landscape can become drier and more vulnerable to ignition. If a fire starts, it can damage vegetation and burn peat, making restoration more difficult. When the next prolonged dry period arrives, parts of the landscape may again be vulnerable.
Land disturbance → Drier conditions → Fire → Ecological damage → Incomplete recovery → Renewed fire risk
Breaking this cycle means addressing the landscape before the next fire begins, not only responding after smoke appears.
7. Riau, Jambi and South Sumatra: Different Places, Connected Risks
Sumatra's fire problem is not uniform. Different provinces have different land-use histories, ecosystems, infrastructure and patterns of fire exposure.
Riau
Riau is frequently discussed in relation to peatland degradation and regional haze. Fires in peat-rich landscapes can be particularly difficult to extinguish completely, and smoke can affect communities far from the ignition point.
Preventing recurring fires requires attention to peat water management, land-use practices and reliable monitoring during dry periods.
Jambi
Jambi also contains peatland landscapes and areas affected by forest conversion and agricultural activity. Fire risk depends on local conditions, including vegetation, water levels, weather and human activity.
The priority is to identify vulnerable locations and ensure that potential fires are investigated and addressed before they spread.
South Sumatra
South Sumatra illustrates how recurring fires can become a major operational challenge. In August 2026, provincial officials reported thousands of hotspots during the month and more than 1,700 fire incidents recorded by August 23. The province also experienced extensive firefighting operations.
The figures underline the importance of sustained prevention and response. They do not, on their own, establish the cause of each fire or prove that all incidents involved peatland.
Across these provinces, the shared lesson is that regional strategies must be adapted to the landscapes and activities that shape local fire risk.
8. The Haze Does Not Stop Where the Fire Ends
The consequences of forest and land fires extend beyond the area that burns.
Smoke can travel with the wind, reducing visibility and exposing people to fine particulate matter. Depending on the concentration and duration of exposure, smoke can irritate the eyes and respiratory system and worsen existing health problems.
Communities near a fire may experience direct smoke exposure, while more distant towns and cities can also be affected when haze spreads.
Severe haze can disrupt daily activities, transportation, schools and economic activity. When smoke crosses national borders, the issue becomes a regional environmental concern rather than a purely local emergency.
The scale of the impact depends on weather, the location and intensity of fires, the type of vegetation burning and the distance between sources and affected populations.
For more detail on the health dimension, see Karhutla and Human Health in Indonesia. For the wider regional consequences, see Indonesia Haze: How Forest Fires Affect Air Quality and Indonesia Wildfires and ASEAN Haze.
9. Why Rain Alone Cannot Guarantee a Solution
Rain can help reduce fire activity by increasing moisture in vegetation and soil. But relying on rainfall alone leaves important problems unresolved.
A fire may continue burning beneath the surface, and a temporary reduction in visible activity does not necessarily mean that all remaining hot areas have been extinguished. If dry conditions return, previously affected areas may become vulnerable again.
The timing and distribution of rainfall also matter. A rainy period in one district does not necessarily provide enough moisture to all affected areas.
That is why authorities use a combination of ground firefighting, aerial operations where appropriate, monitoring, cooling and follow-up checks.
In the longer term, the same effort must be paired with prevention: managing peat water levels, reducing dangerous land-clearing practices, restoring damaged ecosystems and improving early detection.
Rain is an important part of the response. It is not a substitute for changing the conditions that allow fires to recur.
10. What Would Help Break Sumatra's Fire Cycle?
Reducing recurring fires requires action before, during and after the dry season.
Protect peatland moisture. Where peatlands have been drained, appropriate water management and restoration can help reduce their vulnerability to drying and fire.
Improve early detection and verification. Satellite detections should be checked against field conditions where possible. Hotspots are useful indicators, but they are not the same as confirmed fire incidents or burned-area measurements.
Prevent unsafe land clearing. Land users need practical alternatives to burning, supported by clear rules, education and consistent enforcement.
Investigate fires transparently. Authorities should establish the causes of incidents and identify responsibility based on evidence rather than assumptions about nearby landowners or companies.
Restore damaged landscapes. Restoration can help rebuild ecosystem functions, but it must account for local water conditions, vegetation and the history of disturbance.
Strengthen community participation. Local residents often have valuable knowledge about recurring fire locations and seasonal conditions. Community-based monitoring and reporting can help identify problems early.
Track recovery after suppression. Fire management should include follow-up checks to identify remaining hot areas and prevent reignition, particularly in peatlands.
These measures address different parts of the same problem. Fire suppression limits immediate damage, while prevention and restoration aim to reduce the chance that the next fire will occur.
11. Why Sumatra's Fire Problem Matters to Indonesia
Sumatra's recurring fires are not only a seasonal emergency. They raise broader questions about land management, ecosystem protection, public health and the long-term costs of environmental degradation.
When a landscape repeatedly burns, the consequences can accumulate. Vegetation may struggle to recover, peat can be lost, wildlife habitat can be damaged and communities can face repeated exposure to smoke.
Firefighting also requires substantial public resources, personnel, equipment and coordination. Preventing a fire can be less damaging than repeatedly responding after it has spread.
Yet no single measure can solve every part of the problem. Fire risk differs between ecosystems and provinces, and prevention must reflect those differences.
The most effective approach combines reliable monitoring, responsible land management, enforcement, restoration and community participation.
Sumatra's experience shows why the question should not be limited to how quickly a fire can be extinguished. It should also ask why the same landscape remains vulnerable year after year.
Conclusion: The Next Fire Begins Before the Flames Appear
Why do forest and land fires keep returning to Sumatra?
The answer lies in the interaction between vulnerable landscapes, peatland drainage, land-clearing practices, prolonged dry weather and the difficulty of completely extinguishing some fires. When these conditions remain unchanged, the end of one fire season does not necessarily mean the underlying problem has been solved.
Sumatra's fire cycle can be broken only by combining effective emergency response with long-term prevention. Peatlands must be managed carefully, damaged landscapes need restoration, land clearing must be responsible, and the causes of individual fires must be investigated transparently.
The real challenge is not simply to extinguish today's flames. It is to make tomorrow's fire less likely to start.