Kalimantan has some of the world's most important tropical forests and peatlands. It is also one of Indonesia's regions repeatedly affected by forest and land fires.
The pattern is not simply a story about dry weather.
Kalimantan's recurring fires are connected to a combination of peatland conditions, land-use change, vegetation dryness, human ignition, fragmented landscapes and the difficulty of controlling fires once they spread.
In severe years, the consequences extend far beyond the burned area. Smoke can affect communities, transportation and air quality, while fires can damage forests and wildlife habitat.
So why does Kalimantan keep experiencing forest fires?
The short answer is that climate conditions can increase fire risk, but the way land is managed determines how vulnerable many landscapes become to fire.
 |
| Fire burns land in Tumbang Nusa Village, Pulang Pisau Regency, Central Kalimantan, on Sunday (August 30). Photo by ANTARA FOTO/Auliya Rahman |
Why Is Kalimantan So Vulnerable to Fire?
Kalimantan is not one uniform landscape.
The island contains:
- tropical rainforests
- peatlands
- wetlands
- plantations
- agricultural land
- grasslands and shrublands
- settlements
- degraded forests
Each landscape responds differently to fire.
Healthy, humid rainforest is generally difficult to burn under normal wet conditions. But when vegetation dries, peatlands are drained or forests are degraded, the landscape can become much more flammable.
This distinction is important.
A hot and dry season may create favorable conditions for fire, but it does not automatically create an ignition source.
Fire requires both something that can burn and a source of ignition.
Human activities are therefore an important part of the explanation.
Peatlands Are One of the Biggest Pieces of the Puzzle
One of the most important reasons fires can become persistent in parts of Kalimantan is the presence of peatlands.
Peat forms when dead plant material accumulates faster than it decomposes, usually in waterlogged environments.
When peat remains wet, it is relatively resistant to burning.
The problem begins when peatlands are drained.
Drainage lowers the water table and exposes peat to drying. During prolonged dry periods, dried peat can become highly vulnerable to fire.
And unlike a surface fire, peat fires can smolder below ground.
This makes them particularly difficult to detect and extinguish completely.
The Indonesian disaster agency has repeatedly identified peatlands as a major challenge during fire operations. In September 2026, BNPB noted that fires in West Kalimantan were concentrated in peat areas and required intensive cooling to prevent fires from reigniting underground.
This helps explain why putting out the visible flames does not always mean the fire problem is finished.
Land Management Can Increase Fire Risk
Another part of the explanation is land use.
Kalimantan's landscapes have changed substantially through agriculture, plantations, infrastructure and other forms of development.
When natural forests are cleared or degraded, the resulting landscape can become more fragmented.
Forest fragments may be surrounded by:
- plantations
- agricultural fields
- roads
- settlements
- grassland
- shrubland
- drainage canals
These changes can alter local moisture conditions and make fire easier to spread across parts of the landscape.
The important point is not that every plantation or agricultural area causes fires.
Rather, certain land-management practices can increase the probability that an ignition becomes a larger fire, particularly when vegetation is dry and peatlands have been drained.
How Do Forest and Land Fires Start?
There is no single cause behind every fire in Kalimantan.
Potential ignition sources include:
Land clearing
Fire has historically been used in some forms of land preparation because it can clear vegetation quickly and cheaply.
When conditions are dry or winds are strong, however, a fire intended for a limited area can spread beyond the intended boundary.
Agricultural burning
Small-scale burning can also become dangerous when fire escapes control.
The risks depend on weather, fuel conditions, location and how the burning is managed.
Accidental ignition
Fires can also begin unintentionally through human activities.
Deliberate burning
Some fires may be deliberately started for land management or clearing.
Determining responsibility requires evidence from field investigations rather than simply assuming that a nearby land user caused a fire.
This distinction matters because a hotspot is evidence of a thermal anomaly, not proof of who started a fire.
The Ministry of Forestry has emphasized this distinction in its fire monitoring information: satellite hotspots need field verification to establish the actual fire location, cause and burned area.
Why Does Dry Weather Make Everything Worse?
Weather is a major amplifier of fire risk.
During prolonged dry periods:
- vegetation loses moisture
- leaf litter dries
- grasses become easier to ignite
- peatlands can become drier
- fires spread more easily
- firefighting becomes more difficult
Kalimantan can therefore move from a relatively wet landscape to a much more fire-prone environment when rainfall declines for an extended period.
This is one reason why fire risk often increases during the dry season.
But there is an important distinction:
Drought creates favorable conditions for fire; it does not necessarily explain the ignition itself.
That is why preventing fires requires more than waiting for rain.
What Role Does El Niño Play?
El Niño can alter rainfall patterns across Indonesia and increase the likelihood of dry conditions in some periods and locations.
When a strong El Niño coincides with already degraded or drained landscapes, the potential for fire can increase.
However, El Niño should not be treated as a complete explanation for Kalimantan's fires.
A useful way to understand the relationship is:
El Niño → drier conditions → more flammable vegetation and peat → greater fire risk
But another component is needed:
Ignition + available fuel + favorable weather = potential fire
The interaction between climate and land management is therefore more important than blaming any single factor.
For a broader explanation, see El Niño and Indonesia's Wildfire Risk.
Why Do Fires Keep Coming Back?
This is perhaps the most important question.
A forest fire can temporarily disappear without the landscape becoming safe from future fire.
If the underlying conditions remain unchanged, another fire can occur during the next severe dry period.
How the Fire Cycle Repeats
Kalimantan's fire problem can become a self-reinforcing cycle.
Land degradation reduces the landscape's ability to retain moisture and recover naturally. As forests are cleared or disturbed, the landscape can become drier and more fragmented, creating conditions in which fire spreads more easily.
Once an ignition occurs, dry vegetation and vulnerable peat can carry the fire across the landscape. The resulting fire damages vegetation, dries or burns peat, and further weakens the ecosystem.
After the fire, the landscape may be less resilient than it was before. If drainage, land conversion or other disturbances continue, the area can become more vulnerable to another fire during the next prolonged dry period.
In simple terms, the cycle looks like this:
Degraded land → Drier landscape → Fire → Ecological damage → Weaker recovery → Greater fire risk
This is why recurring fires cannot be addressed only when flames appear. Breaking the cycle requires improving the condition of the landscape before the next fire starts.
Why Are Peat Fires So Difficult to Extinguish?
Surface fires can sometimes be reached directly with water or other suppression techniques.
Peat fires are different.
A fire may continue smoldering beneath the surface even after visible flames disappear.
Firefighters may therefore need to:
- locate underground hotspots
- inject or apply water
- cool surrounding areas
- monitor the site after suppression
- prevent reignition
This requires more time and resources.
It also explains why large firefighting operations can continue even when the visible flames appear to have decreased.
Kalimantan's 2026 Fire Season
The 2026 fire season demonstrates how quickly conditions can change.
On August 20, BNPB reported 1,487 hotspots across Kalimantan, with 767 in Central Kalimantan and 560 in West Kalimantan.
By September, official monitoring continued to identify Kalimantan as one of the main areas requiring intensive fire control.
On September 14, the Ministry of Forestry reported 689 high-confidence hotspots in Central Kalimantan on the previous day's monitoring, while West Kalimantan also remained among the priority areas.
Later in September, BNPB reported that Central Kalimantan had the largest area still requiring suppression among the six national priority provinces.
These numbers should be interpreted carefully.
A hotspot is not the same thing as a fire incident, and neither is automatically equivalent to the total burned area. One fire can generate multiple satellite hotspots, while some fires may not be detected in the same way by satellites.
That is why official assessments combine satellite monitoring with field verification.
Central Kalimantan: A Major Fire Hotspot
Central Kalimantan has repeatedly emerged as one of the most important fire-prone areas in Indonesia.
The province contains extensive peatlands and has experienced major landscape changes.
In 2026, it was repeatedly among the provinces with the highest number of detected hotspots.
BNPB's September reporting also identified Central Kalimantan as a priority for ground and aerial firefighting operations.
The province illustrates the interaction between:
- peatland
- seasonal dryness
- land use
- fire ignition
- difficult access
- firefighting capacity
West Kalimantan: Forest, Peatland and Wildlife Pressure
West Kalimantan has also experienced significant fire activity.
BNPB reported that the province had recorded approximately 38,310 hectares of indicative burned area by September 28, 2026, although burned-area figures can change as official data are updated and verified.
The province also illustrates the connection between fire and wildlife conservation.
In 2026, the Ministry of Forestry reported the rescue of wildlife affected by fires in West Kalimantan, including orangutans.
This connects the wildfire problem to a broader ecological issue.
A fire does not only remove vegetation.
It can also destroy feeding areas, nesting sites and habitat corridors.
For more on this connection, see Orangutans and the Impact of Indonesian Forest Fires.
Do Companies Cause Kalimantan's Forest Fires?
This question requires careful treatment.
Companies can have legal responsibilities for preventing and controlling fires on land under their management. Where authorities find violations, companies may face administrative or other legal action.
In August 2026, Indonesia's Ministry of Forestry announced administrative sanctions against six companies after inspections identified fires covering a combined 1,511.55 hectares within their managed areas in West, Central and East Kalimantan. One company received a business-permit suspension alongside government enforcement measures because the fires were described as extensive and recurring.
However, the existence of a fire inside a concession does not by itself prove that a company deliberately started it.
Responsibility depends on evidence concerning:
- the location of the fire
- land ownership or management
- fire-prevention obligations
- management practices
- the origin of the ignition
- the company's response
- relevant legal findings
This distinction is essential for credible environmental reporting.
Why Fire Prevention Is Harder Than Firefighting
Once a large fire has started, governments can deploy:
- firefighters
- water pumps
- helicopters
- water bombing aircraft
- patrol aircraft
- satellite monitoring
- weather modification operations
But these tools address the fire after ignition.
Prevention requires changing the conditions that allow fires to become large.
That means:
- maintaining peatland water levels
- improving land management
- preventing uncontrolled burning
- detecting fires early
- maintaining access for firefighters
- strengthening community-based prevention
- enforcing fire-prevention responsibilities
- restoring degraded landscapes
The goal should therefore be to prevent the landscape from becoming highly flammable in the first place.
What Can Be Done to Reduce Kalimantan's Fire Risk?
Protect and restore peatlands
Keeping peat wet is one of the most important ways to reduce peat-fire vulnerability.
Improve land-use planning
Development should account for fire risk, ecological sensitivity and landscape connectivity.
Strengthen early detection
Satellite systems can identify potential hotspots quickly, while ground teams are needed to verify and respond to them.
Support local fire prevention
Communities living near fire-prone landscapes can play a critical role in early detection and prevention.
Enforce land-management responsibilities
Companies and other land managers need effective systems for monitoring, prevention and response.
Restore degraded landscapes
Restoration can improve ecological resilience and reduce the conditions that allow repeated fires.
Prepare before the dry season
Fire prevention should begin before the landscape becomes critically dry.
Waiting until smoke is already visible is often too late.
Why Kalimantan's Fire Problem Matters Beyond Kalimantan
The consequences of Kalimantan's fires do not necessarily stop at the boundary of a burned area.
Smoke can affect nearby communities and, under certain atmospheric conditions, travel across national borders.
Forest and peat fires can also release stored carbon and damage biodiversity.
The loss of habitat can affect species long after the flames disappear.
And repeated fires can undermine the ability of forests and peatlands to recover.
This is why Kalimantan's fire problem should be understood as part of a larger environmental system involving climate, forests, peatlands, biodiversity, public health and land management.
The Bigger Lesson
Kalimantan keeps experiencing forest fires because several risk factors repeatedly come together.
Dry conditions can make vegetation and peat more flammable.
Land-use changes can alter the landscape.
Human activities can provide ignition sources.
Drained peatlands can sustain difficult-to-control fires.
And once a landscape has been degraded, it may become more vulnerable to another fire.
Climate variability can make some years much worse than others, but climate alone does not explain the entire problem.
The deeper challenge is managing a landscape where forests, peatlands, plantations, agriculture and communities increasingly exist side by side.
Conclusion
Why does Kalimantan keep experiencing forest fires?
Because fire risk is created by an interaction of weather, vegetation, peatland conditions, land use and human activity.
Some years bring much drier conditions and dramatically increase the danger. But recurring fires also reflect longer-term changes in the landscape.
That is why the solution cannot be limited to putting out flames.
Kalimantan needs effective prevention, healthy peatlands, responsible land management, rapid detection, strong local participation and long-term forest restoration.
The most important question is not simply how to fight the next fire.
It is how to make the landscape less vulnerable to the next fire in the first place.