Indonesia: Fire Damages in East Kalimantan in 1997-98 Related to Land Use – ERS-SAR Inventory Results (IFFN No. 23)

Fire Damages in East Kalimantan in 1997-98 Related to Land Use:
ERS-SAR Inventory Results

(IFFN No. 23 – December 2000, p. 25-29)


The province of East Kalimantan was the area worst affected by the fires during the 1997-98 forest and land fires in Indonesia. The daily NOAA-AVHRR hot spot maps provided by the Integrated Forest Fire Management (IFFM) project showed that between late 1997 and May 1998 the fires affected the entire Mahakam basin, its tributaries and spread as far as the Sangkulirang peninsula (Siegert and Hoffmann 1999). Many forest concessions as well as forest and industrial crop plantations were severely affected by wildfires. In August 1998 the Sustainable Forest Management Project (SFMP) proposed an “Actions after forest fire in natural forest concessions program” to the Ministry of Forestry and Estate Corps (see Huljus and Hinrichs in this volume). As a data basis for this five-step proposal IFFM and SFMP jointly conducted on request of the Ministry of Forestry a study using ERS-2 SAR space borne radar images to disclose the size of the fire affected area for the entire province according to all land uses.

The Directorate of Forest Inventory and Land-use Planning and the two projects further agreed to develop a revised forest land use map for East Kalimantan, exposing the actual locations and boundaries of the current forest and industrial crop utilization right holders. An overlay of the radar fire survey results with the actual forest land use boundaries should reveal the fire damages for each land use. This data is intended to support the provincial agencies to revise their current land-use plan of East Kalimantan. It shall furthermore be used as basis for the implementation of correct salvage felling activities, rehabilitation measures and adjustments of the long term forest planning in each natural forest concession. Moreover, the data is needed within the IFFM Fire Information System to point out future fire hazard and fire risk zones in East Kalimantan and hence support fire management planning, prevention work and fire suppression (Hoffmann et al. 1999b).

Assessing the fire damages with ERS-SAR radar technology

Radar technology employs the microwave portion of the electromagnetic spectrum and can therefore penetrate clouds and haze, which hampers the usually in the tropics employed optical sensors. The radar detection process is an active process which entails transmitting short pulses of microwave energy towards the earth’s surface and records the reflections received from various objects. The reflection received is the so called radar backscatter. With ERS-SAR radar the loss of biomass due to fire can be assessed by analyzing changes in the backscatter signal in a radar image before and after the fire (Hoffmann et al. 1999a, Siegert and Rücker 1999).

For the study multi-temporal radar images of August 1997 and April/July 1998 of East Kalimantan were purchased. After several calibration flights and field tests 4 damages classes were distinguished:

  • 25-50% fire damage
  • 50-80% fire damage
  • >80% fire damage, dead woody biomass still standing
  • >80% fire damage, biomass consumed

Damage class 3 was included in order to justify the conditions mostly found in the (peat-) swamp forest of the Middle Mahakam lake area where almost the entire peat swamp forest was destroyed by fire but mostly dead trees (woody biomass) are still standing. This condition provides a high future fire risk given the immense amount of fuel material remaining after the fires. Furthermore damage level 4 describes the general situation found in forest plantations and areas of already very degraded forest, bush and grassland as well as farmland.

A basic verification was done by overlaying fire locations depicted by NOAA-AVHRR between August 1997 and May 1998 in East-Kalimantan onto the ERS-SAR damage classification result. The outlined area of the ERS-2 SAR burn scar map corresponded well with the fire affected area depicted by the NOAA-AVHRR.

Furthermore a detailed verification was conducted by comparing the radar interpretations with digital video tapes taken during two further flight surveys in March/April 1999. Severe errors like if unburned areas of the video taped flight were classified as burned in the ERS-SAR image, occurred at approx. 5%. Therefore we conclude that the burned area mapped by ERS-2 radar has a high credibility and indicates even a slightly underestimate of the size of the 1997/98 fire affected area in East Kalimantan.

The land status data was gathered with the help of INTAG Bogor and BIPHUT Samarinda and digitized. Several problems arose during compiling the official data due to overlaps, gaps and inconsistencies in the official systems. The results therefore only reflect the best possible data on a provincial scale. The developed land use map was overlaid with the result of the radar burn scar assessment using a GIS in order to determine the damage level per land use right holder.


The results of the ERS-SAR radar inventory showed that the 1997/98 fire was the worst ever fire catastrophe encountered in East Kalimantan. The area affected by fire totalled 5.2 million ha, equalling ca. 25% of the entire province. Almost 2.3 million ha belong to natural forest concession areas (56 concessions), 0.4 Million ha to protected forests, 0.9 million ha of forest plantations (30 concessions) and 0.7 Million Ha to industrial crop plantations. Almost 75% of the plantation areas (forest, oil palm, etc.), that were located within the 1997/98 fire zone, have been fire affected, a large number of them severely. This demonstrates the very high fire risk of all types of plantations. Table 1 shows an overview about the fire damage related to the current land use.

The Ministry of Forestry and Estate Crops received a detailed list of all fire affected areas with the names of the responsible utilization right holder. Active rehabilitation of the 2.3 million ha fire affected natural forest concession areas is mainly needed in forests with a fire damage greater than 50%. It can be expected that most of the former well stocked areas with a 25-50% fire damage will recover naturally, especially if further damage through logging does not occur. This still leaves a rehabilitation area of almost 1.6 million ha in the natural forest concessions alone. Funding (incentive systems) and investment security are the largest obstacles to be overcome before effectively starting forest rehabilitation. In 1982/83 a severe fire catastrophe had already occurred in East Kalimantan, damaging 3.5 million ha of land and forest.

Tab.1. Overview of area burned in East Kalimantan, Indonesia, in 1997-98 related to land-use classes and damage levels

Damage Classes

Land Status

Total Area in East Kalimantan [ha]

Burned Area [ha]

% Burned

25-50 %

50-80 %

>80 %

(Dead Trees still standing)


(without standing large trees: pre-fire degraded or converted)

Natural Forest Concession area (HPH)








Forest Plantation (HTI) Area








Estate Crop (Perkebunan) Area








Total Protected Area (HL)








Undefined Land Use (e.g., farmland)














Out of this 0.8 million ha was primary forest and 1.4 million ha was logged-over forest (Lennertz and Panzer 1983). In 1997/98 the area of the 1982/83 fire burned again to an even greater extent. The recent loss to forest economy is immense, considering short and long term economic losses.

Table 2 shows a simple vegetation classification of the 1997/98 fire affected area. The fires mainly occurred in the generally already logged low land Dipterocarp Forest and on open, degraded or converted areas. But also large parts of the wetlands and swamps were for the first time in recent history fire affected, since these areas had almost completely dried up due to the extreme drought.

Tab. 2: Damaged areas after land-use and vegetation based on ERS-SAR 2 data from August 1997

Vegetation and land use classes




Open land, alang alang, bushland




Lowland Dipterocarp forest




Farmland mixed with degraded forest areas, including Forest and Estate crop plantations *




Mangrove forest




Shrimp ponds




Swamp (peat swamp) forest








Mountainous region, mainly highland Dipterocarp forest








* Vegetation interpretation with the ERS-SAR allows no clear distinguish between plantations and degraded forest

After the 1997/98 fires the forest is much more susceptible to fire, due to degradation and accumulation of fuel and thus, at present, even during normal dry seasons it will be prone to fires. Furthermore, El Niño events are predicted to occur more frequently than in the past, creating conditions that could trigger even more, and more severe, fires in the future. Under these conditions, land use conflicts between the local people and concession and plantation owners, carelessness and land clearing using fire can easily bring forest activities to an end. Already many degraded and undefined land use areas are prone to grassland (alang-alang) cycles, where fire becomes a part of the succession cycle. Therefore fire management is a key issue in achieving the goal of sustainable forest management.


Hoffmann A. A., A.Hinrichs, and F.Siegert. 1999a. Fire damage in East Kalimantan in 1997/98 related to land use and vegetation classes: Satellite radar inventory results and proposals for further actions. With contributions from G.Ruecker, L.Christy, and B.Yuliarso. Sustainable Forest Management Project (SFMP) & Integrated Forest Fire Management (IFFM) Project, Indonesian Ministry of Forests and Estate Crops (MoFEC) and German Technical Cooperation Agency (GTZ), Samarinda, Indonesia. Report No.1.
Hoffmann, A. A., L.Schindler, and J.G.Goldammer. 1999b. Aspects of a Fire Information System for East Kalimantan, Indonesia. Proceedings of the 3rd International Symposium on Asian Tropical Forest Management, Samarinda, East Kalimantan, Indonesia, 20-23 September 1999.
Lennertz, R., and K.F.Panzer. 1983. Preliminary assessment of the drought and forest damage in Kalimantan Timur. GTZ-TAD Report, Germany.
Siegert, F., and A.A.Hoffmann. 1999. The 1998 forest fires in East Kalimantan (Indonesia): A quantitative evaluation using high resolution, multitemporal ERS-2 SAR Images and NOAA-AVHRR Hot Spot data. Remote Sensing of the Environment (in press).
Siegert, F., and G.Rücker. 1999a. Evaluation of the 1998 forest fires in East-Kalimantan (Indonesia) using multitemporal ERS-2 SAR images. Earth Observation Quarterly 61, 7-12.
Siegert, F., and G.Ruecker. 1999b. Use of multitemporal ERS-2 SAR images for identification of burn scars in South East Asian tropical rainforest. Int. J. Remote Sensing (in press).

Contact addresses:

Anja Hoffmann
Integrated Forest Fire Management IFFMGTZ,
Jln Harmonika, Perkantoran Dinas Kehutanan
Samarinda 75001 Kalimantan Timur

Tel: +62-541-32625
Fax: +62-541-33519

Alexander Hinrichs
Promotion of Sustainable Forest Management in East Kalimantan Project (SFMP)
P.O.Box 1087
Samarinda 75001 Kalimantan Timur

Tel: +62-0541-733434
Fax: +62-0541-733437

Florian Siegert
Ludwig Maximilian University, Department of Biology
Luisenstr. 14
80333 Muenchen



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