peatwise - peat fire characteristics -...

Laboratory of Geoecology, Division of GeoscienceGraduate School of Environmental Earth Science

Hokkaido University

Peat fire characteristics of tropical peatland in Central Kalimantan,

Indonesia

Aswin Usup

116 August 2006

Problems in tropical peatland

Logging

Settlements

Farmland

Canal

Chapter 1. BackgroundGeneral view of tropical peatland

Kalimantan 8.6 M ha(44% of Indonesian peatland)

Importance of tropical peatland

Stores significantly large amount of carbon

Conservation of natural ecosystem

Climate regulation

Hydrological system

Natural resources

Peat fire 2004 in Palangka Raya2

Burning every year not only in El Nino event

0

50,000

100,000

150,000

200,000

250,000

300,000

1984

1985

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

Years

Bu

rned

are

a, h

a

Source: Department of Forestry, Indonesia, 2002.

Chapter 1. BackgroundTotal burned area in Indonesia from 1984 to 2001

El NinoOil Palm

Rice plantation

Transmigration

Even in C.Kalimantan

3

Chapter 1. BackgroundBad effects of tropical peatland fire on environment in case 1997

1. Damage on peatland: 0.73 M ha of peatland in Central Kalimantan*

2. Carbon emission from Central Kalimantan: 0.19 – 0.23 Gt of carbon release to the atmosphere through peat combustion*

3. Damage on natural ecosystem: 9 National Parks in Indonesia were damaged

4. Damage on social activity and human health in Southeast Asia

Haze in Palangka RayaCity

Peatland fire

Hotspots distribution 1997

4(*Page et al, 2002)

Boreal peat Tropical peat

1. Fire Behavior: Ignition process, smoldering front, spread rate and peat fire temperature

4. Fire ecology, carbon released, and Social economic

Rieley, (1985), Boemh, (2001), Siegert, (2001) Page, (2002), Muraleeharan, (2002) and many others

Kasischke, (1995)

Christjakov (1983), Wein (1983), Hungerford (1995), Hartford (1989) Miyanishi (2000) and others

No data

2. Fuel composition: Crown, Surface and Ground

Bilgili Esturgul, (2003), Angge, (2002), Carter (2004), Domingus Viegas, (1998), and others

No data

3. Combustion characteristics of fuels: Flammability and calorific value

Ratjh, (2003), Dimitrakopoulus, (2001) Miyanishi, (2000), Nunes Regueira, (1996)Mongomery, (1971), and others

No data

Chapter 1. BackgroundReview of previous study

5

The objectives of this study are:

1.To clarify the peat fire behavior in tropical peatland

2.To examine the fuel composition, and

3.To evaluate combustion characteristic of fuel materials in the laboratory

Objective

6

Peatland fire

Combustion characteristics of peat

Monitoring climate & hydrology

•Preheating •Ignition, flaming & glowing temperature•Volatile matter•Degradation rate•Calorific values

• Front type• Spread rate• Temperature

• Crown • Surface• Ground

• Rainfall• Temperature• Humidity• S. radiation• Wind speed/direction

Peat fire characteristics

Proposal on peat fire control

9 study sites 1 study site

Field ObservationLaboratory Analysis

FuelsIn peatland

Peat fire behavior

Damage level

•Fuel loss•Fire depth• Carbon loss

TG-DTA & Bomb Calorimeter

Framework of the study

7

Chapter-1 IntroductionChapter-2 Study area and methodology

Chapter-3 Peat fire behavior in tropical peatland3.1. Fire regime in tropical peatland3.2. Horizontal and vertical peat fire front 3.3. Peat moisture near smoldering zone 3.4. Spread rate of peat fire3.5. Temperature in peat layer during a fire event 3.6. Peat fire damage 3.7. Concluding remarks

Chapter-4 Fuel materials in tropical peatland4.1. Fuel composition in secondary peatland forest 4.2. Fuels composition in the ground 4.3. Distribution of woody peat in the ground 4.4. Fuel loss by fire and carbon loss4.5. Concluding remarks

Chapter-6 General discussion

Chapter-5 Combustion characteristics of fuel materials5.1. Thermogavimetry (TG) analysis

5.2. Differential thermal analysis (DTA)5.3. Derivate thermogravimetry (DTG) analysis5.4. Calorific value 5.5. Concluding remarks

Contents of thesis

8Chapter-7 Conclusions

2o 20’S

2o 30’S

2o 40’S

2o 50’S

2o 10’S

113o 50’E 114o 0’E 114o 10’E 114o 20’E

Palangka Raya

Pulang Pisau

Garung

Kahayan River

Sebagau River

University plot

Plot-1

P-2P-3P-4

P-6

P-7

P-8

P-9

P-5

N0 20

km

Chapter 2. Study area and methodology

Peatlanddistribution in

Borneo

Peatland distribution in Central Kalimantan

Canal

Basin/domed peatland

Java Sea20 0 20 40 Km

Palangka Raya

Basin/domed peatland

Java Sea20 0 20 40 Km

Palangka Raya

9: Study site

Chapter 3 Peat fire behavior in tropical peatland

10

1. Fire propagation regimes in tropical peatland

2. Horizontal and vertical peat fire front

3. Spread rate of peat fire

4. Peat moisture near smoldering zone

5. Temperature in peat layer during a fire event

6. Peat fire damage

Peat fire

Surface fire

Crown fire

Spotting

Brands

Surface fire

Peat

fire

Peatland fires

Crown fire

3.1. Fire propagation regimes in tropical peatland

11

1. Horizontal fire line

Wind direction

Burn area

Iron sticks

Fire front

Method3m by 3m quadrate75 cm length iron sticks50 cm intervalsPlace: plot 3, 5, and 7Observation:1-14 August 2002

3.2. Horizontal and vertical fire line of peat burning

Burned area

Peat fire line in plot 3Six days observation

8/1

8/6

3m

2

1

0Cross section A

B

12

8/68/5

8/4

8/3

8/2

Active

Active

Extinguished

Extinguished

a. Surface peat fire

Surface peat fire at plot 3

2. Vertical fire line

0

10

50 200 cm100

Peat soil

20

150

Fire frontAsh

Depth (cm)

3.2. Horizontal and vertical fire line of peat burning

13

A B

b. Subsurface peat fire

Subsurface peat fire at plot 5

0 20 40 cm

Depth (cm)

0

15

30

Overhanging

Fire front

Ash

Central KalimantanPeat fires (20 cases)

Surface peat Subsurface peat

42 – 155 12 – 60

Location: Plot 3,5 and 7Date: 1-14 August 2002 (cm/day) (cm/day)

Russian peat 12-240

Canadian peat 72-288

Australian peat 100

Wein, 1983

Case of boreal peat fires

3.3. Spread rate of tropical peat fire

Reference

Chistjakov, 1983

Wein, 1983

14

Spread rate

Smoldering Zone

24%

31%

61%

52%

62%

68%

42%

63%

70%Ash

Peat soil

Plot 3

5 10 100 cm

5

10

15cm

Ash

Smoldering Zone

23%

31%

50%

37%

61%

63%

52%

62%

59%Ash

Peat soil

Plot 5

5 10 100 cm

Peat moisture near smoldering zone at plot 3 and 5

Peat moisture near smoldering zone in Seney NWR Michigan USA

(Hungerford, 1996)

Smoldering zone

5 10cm

5

10

15cm

1 meter

15 cm

5 cm

Organic layerGlowing Zone

79%

61%

82%100%

89%

100%

5 cm

10 cm

Mineral soil

Moisture content near smoldering zone

Burn Hole

0

3.4. Peat moisture near smoldering zone

15

Recorded by Thermal video system (TVS 600) Avio Neo Thermal,

on 15 September 2004.

Temperature Level

600oC200 400

3.5. Temperature in peat layer during a fire event

16

Temperature distribution in a peat fire

surface

10 cm

0

50

100

150

200

250

300

Temperature (oC) 275oC Fire temperatures measurement

Tool :Chromel alumel thermocouples of 0.5 mm, with stainless steel sheath in a 6 channel data logger (KADEC-US Kona System Co. Ltd. Japan)

Date : 20 – 27 August 2002.

18

(≈ignition temperature)


Front temperature of surface peat fire

Days of August 2002

20 21 22 23 23 24 25 26 27

275oC

Surface

10 cm0

50

100

150

200

250

300

7:40 8:40 9:40 10:40 11:40 12:40

Time (minute)

Tem

pera

ture

,o C The temperatureabove 250oC persisted about 30 minutes

22 August 2002

0

100

200

300

400

500

600

Temperature, oC

0 5 10 15Peat was not ignited

1-2 minutes heating by high

temperature of surface fire was not enough to

ignite peat layer

Time (Minute)

0 cm1m above surface

Location : University siteDate : 16 September 2002

19

275oC (≈ignition temperature)


Slash and burn experiment on peat ignition

20


Woods burning experiment on peat ignition

0

100

200

300

400

500

600

700

800

0 10 20 30 40 50 60 70

Time (Minute)

Temperature, oC

0cm

5cm

20 Min

Peat ignitedAt temperature ≈ 275oC

University site

Peat loss by fire:

Maximum = 80 cm

Averages = 56 cm

Measured at 1 m interval

20

40

60

80Depth (cm) Peat surface

after burning

Peat soil

0

3.6. Fire damage

10 20 30 40m0

Canal

NorthInitial peat

surface

A part of measurement area21

Change of micro topography

Initial peat surface

3.6. Fire damage

22

Burned area and mean depth of peat fire penetration of each plot study

Heavy

Heavy

Heavy

Heavy

Heavy

Heavy

Heavy

Medium

Heavy

Heavy

Heavy

Forest damage level*)

*) ITTO, 1994 Forest damage level: Dead of trees caused by fire (%)Light damage < 20%; medium; heavy > 60%

Burned area

(ha)Depth (cm)

P1 2.0 46

P2 3.0 38

P3 1.2 30

P4 2.6 53

P5 1.4 33

P6 5.0 38

P7 1.2 40

P8 0.9 20

P9 1.2 32

University 3.0 56

Mean 2.15 39

Peat Damage

Plot

Peat fire characteristics in the field:Peat IgnitionSmoldering temperature: 125-500oC Duration of heating >20 minutesDry wood on the peat surface: necessary for long heating Peat moisture < 40 % dbFire in the slash and burn area: rarely ignite peat

Fire ExpansionFlaming temperature: around 300-400oC Type and spread rate of fire front expansion:

Surface :42-155 cm/day Subsurface :12-60 cm/day

Damage LevelMaximum depth of peat loss:80 cmAverage depth of peat loss : 39 cmSubsurface peat fire : heavy forest damage level

Chapter-3 Concluding remarks

23

1. Fuel composition in secondary peatlandforest

2. Fuels composition in the ground

3. Distribution of wood in the ground

4. Fuel loss by fire

5. Carbon loss by fire

Chapter-4 Fuel materials in tropical peatland

24

1. Crown fuelsLocation : University plotSelection : Live and standing dead treesSize : 20m x 20m (4 plots)Weight : 2 trunks of 5, 10 and 20 cm in

diameter (fresh weight) and 5 pcs(each) for oven dry 80oC for 24 hrs

2. Surface fuels

Location : University plot

Selection : Grass, litter, wood debris, and fallen wood

Size : 20m x 20m (4 plots)

Weight : before and after 800C oven dry for 24 hrs

3. Ground fuels

Location : University, plot 3, 5 and 7

Selection : grass root, wood and Coarse peat >2 mm mesh size

PeatFine peat <2 mm mesh size

Size : 1m x 1m x 1m (3 plots each)

Weight : Before and after 1200C oven dry for 24 hrs

4.1. Fuels in secondary peatland forestObservation methods

25

Fuels in another region(In tropical forest of Para Brazil)

Araujo, et al, (1999)

1. Crown fuels(Leafs and trunk)

188.7 ton/ha

2. Surface fuel(Litter and Fallen trunk)

45.0 ton/ha

Total 233.7 ton/ha

The fuel composition about 80% in the

ground

80.4

Fuels in Secondary peatlandforest (This study)

*) Calculated for 1 m in depth

Fuel Components

1. Crown fuels(Leafs and trunk)

2. Surface fuels(Grass, litter, wood

debris, fallen wood)

ton/ha %

29.7 8.0

43.1 11.6

300.0

Total 372.8 ton/ha

3. Ground fuels *)(Grass root, wood,

coarse and fine peat)

4.1. Fuels composition in secondary peatland forest

26

Dry weight (%)

Depth (cm)

0000 10101010 20202020 30303030 40404040 50505050 60606060

30-50

15-30

0-15

Coarse peat

Fine peat

Wood

Grass root

Wood

Grass root

Coarse peat

4.2. Fuels composition in the ground

27

Legend

5 m

0-15 cm deep

0

50

100

150

200

1 2 3 4 5 6 7 8 9 10

0

50

100

150

200

1 2 3 4 5 6 7 8 9 10

Equivalent Diameter cm

Amount of wood

(Pieces)

0

50

100

150

200

1 2 3 4 5 6 7 8 910

15-30 cm deep

30-50 cm deep

0

20

40

60

80

100

0 1 2 3 4D

epth

(cm

)

Wood Coarse and fine peat

4.3. Distribution of wood in the ground

28

These big woods are distributed in deeper layer

Unburned area (5 samples)

Burned area (5 samples)

Legends

Method to calculate of fuel loss by fire an example of Plot 5

Mb: Fuel dry weight of unburned area

Ma: Fuel dry weight of burned area

To PulangPisau

100 m

50

0

120 m

1m2

Transect lines

Trans Kalimantan Highway

N

0

1m2

60

To PulangPisau

100 m

50

0

120 m

1m2

N

Burned area

0

1m2

60

4.4. Fuel loss by fireObservation methods

Mass loss caused by fire:

M = Mb - Ma

29

1m2Burned area

Unburned area

Unburned area

Mean mass loss from 9 plots: 109 ton/ha

Percentage of fuel loss by fire

Ground component (%)

Grass root 8.0

Wood 9.2

Coarse peat 27.9

Fine peat 30.7

Ground fuels 76%

Surface fuels 24%

30

Ground fuel loss by fire (%)

4.4. Fuel loss by fire

Mb= A x B x E (Seiler & Crutzen 1980)

Mb= Biomass loss by fireA = Burned areaB = Biomass loading E = Burning efficiency (%)

Carbon release from peatland fire

Surface fuels10.6 t CO2/ha (25%)

Ground fuels31. 8 ton CO2/ha(75%)

31

4.5. Carbon release

• Biomass � 45% of C, and 90% of CO2 (Seiler & Crutzen, 1980)

• Peat � 50% of C, and 77% of CO2 (Yakelson, et al 1997)

Boreal forestRussian Surface fuel : 8.6 ton CO2/ ha

North America Surface fuel : 7.0 ton CO2/ ha

(Conard et al, 2002)

Total = 42ton CO2/ha

The case of 1997 fires in Indonesia

C. Kalimantan: 350 ton CO2/ha(Page et al, 2002)

Sumatera : 42 ton CO2/ha (Murdiyarso et al, 2002)

Fuel composition of secondary peatland forest

Ground fuels : 80% of total dry weight

Surface and crown fuels : 20% of total dry weight

Ground fuels composition:

Grass root : 8%, decreased with depth

Wood : 9%, increased in deeper layer

Coarse peat : 38%, decreased with depth

Fine peat : 45%, distributed in all layers

Fuel loss and carbon release:Average of fuel loss : 109 ton/haCarbon release : 42.38 ton CO2/ha

(75%) from ground fuels

Chapter-4 Concluding remarks Fuel materials in tropical peatland

32

1. Thermogravimetry (TG) analysis

2. Differential Thermal Analysis (DTA)

3. Derivative Thermogravimetry (DTG) analysis

4. Calorific value of peat combustion

Chapter 5. Combustion characteristics of peat

33

1. TG-DTA: Thermogravimetry and Differential Thermal Analysis

2. Bomb Calorimeter

Chapter 5. Combustion characteristics of peat

34

Bomb Calorimeter, IKA C7000 TG DTA Seiko 3600

Reference (Al2O3)

Apparatus

TG DTA curves of fine peat at 20-40 cm in depth

DT

A (

mJ

min

-1)

-100

-50

0

50

100

150

200

250

50 100 200 300 400 5000000

20202020

40404040

60606060

80808080

100100100100

Mas

s (%

)

TG curve

DTA curve

Water

volatiles matter

Chars

Non ignitableGases

Ash

Temperature, oC

Endothermic

Exothermic

Chapter 5. Combustion characteristics on peat

35

Ignition Temp.

Preheatingtemperature

Peak Flaming Temp

Peak Glowing Temp

TG DTA curve analysis

Core0

20

40

60

Depth (cm)

0 - 20 cm

20–40 cm

40-60 cm

Fine peat

Coarse peat

Fine peat

Coarse peat

Fine peat

Coarse peat

Sieve: 2 mm mesh

Sampling : at University plotDate : 18 August 2002

Dried air for 2 weeks

Chapter 5. Combustion characteristics of peatPeat sample and preparation

36

5. 1. Thermogravimetry (TG) analysis

The composition of the basic materials of peat*)

*) From TG curves, in percentage

37

40-60

20-40

0-20

Peat depth, cm

0% 20% 40% 60% 80% 100%

40-60

20-40

0-20

Peat depth, cm

Composition of the basic material, %

water Non Ig. gases Volatile matter Char

Ash

Coarse peat

Fine peat

5. 2. Differential Thermal Analysis (DTA)

Temperature characteristics of peat combustion

Coarse peat

0

100

200

300

400

500

Temp, C

Fine peat

0

100

200

300

400

500

0 - 20 cm 20 - 40 cm 40 – 60 cmPeat depth, cm

Temp, C

Preheating

Ignition

Flaming

Glowing

Legend

Fine peat

Coarse peat

38

Exo

Endo

5.2. DTA curve analysis

39

20-40 cm

0-20 cm

40-60 cm

Coarse peat

20-40 cm

0-20 cm

40-60 cm

Fine peat

Pattern of DTA curves on peat combustion

Flat peak means longerglowing combustion

Meranti (Shorea spp)

Wood

Ignition temperature (oC) 256 259

Flamming temperature (oC) 330 339

Glowing temperature (oC) 432 477

Moisture content (%) 20.44 8.30

Volatile matter (%) 52.43 66.00

Max. degradation rate (mg/min) 3.87 2.22

Calorific value (kJ/g) 18.90 18.87

Wood (Shorea, spp)Parameters Coarse peat 0-20 cm

0

1

2

3

4

0 100 200 300 400 500

Temperature, C

Volatile matter release rate

(mg/min)

Maximum value of volatile matter release rate

DTG curve of coarse peat at 0-20 cm in depth

5.3. Derivative Thermogravimetry (DTG) analysis

Volatile matter release rate =dTG/dt

40

DTG curve

Volatile matter release rate of peat combustion

5.3. Derivative Thermogravimetry (DTG) analysis

41

0

1

2

3

4

0-20 cm 20-40 cm 40-60 cm

Peat depth, cm

dm/dt (mg/min) Coarse peat

Fine peat

5.3. Calorific value Bomb calorimeter analysis

42

Calorific values of peat

17

18

19

20

0-20 cm 20-40 cm 40-60 cm

Peat depth, cm

Calorific value, kJ g-1

Fine peat

Coarse peat

Chapter 5. Concluding Remarks

1. 57% non ignitable materials and 43% ignitable materials

2. Various combustion temperatures:

Preheating temperature :

-Surface peat : 96 - 103oC

-Subsurface peat : 141 - 151oC

Ignition temperature : 256 - 277oC

Flaming temperature : 310 - 330oC

Glowing temperature : 411 - 438oC

The combustion characteristics of peat:

3. Volatile matter loss rate : 1.12 mg/min

(Coarse peat in the surface: 3.87 mg/min)

4. Calorific value : 18-19 kJ/g

43

Surface fireSurface fire

Surface peat fire

Subsurface peat fire

New surface fuels in next fire season

6. General Discussion

Crown, Surface

&Ground

fuels

Crown fire

Light

Fuel types

Me-dium

Heavy

Fire types Damage levels

Schematic diagram of peatland fire dynamics

80%Ground

fuel

CrownSurface

Wood burningLong burning time

Higher temperature >700 oCInitial condition of peat

for ignition• Peat MC ≤40%• Heating duration > 20 min• Ignition temperature 275oC

Ignition Point

Surface peat fireSurface fire

Peat soilSmoldering zone

Peat soil

Surface fire

Subsurface peat fire

Surface peat fire

Peat soil

Surface fire

Overhanging

Smoldering zone

Ignited

Penetrated

Surface peat fire• Moved 3 times faster than subsurface peat fire

• Surface peat contain many coarse peat.

Forest damged by fire in Central Kalimantan

1.Important combustion parameters of tropical peat were clarified and the understanding of fire behavior in the field:

• Smoldering zone temperature

• Fire spread rate on surface and subsurface peat fire

• Peat moisture, duration of heating and forest damage level

• Volatile matter and char content of peat,

• Flaming and glowing temperature

• Volatile matter release rate

• Calorific values of peat

Chapter 7. Conclusions

44

2.Fuel composition of secondary peatland forest: 80% are stored the ground

3.Two types of peat fire expansion: surface peat fire and subsurface peat fire.

4.Dry wood on the ground and coarse peat in the surface layers: important for peat ignition.

5.Subsurface peat fire: heavy damage on peatland forest

Chapter 7. Conclusions

45

Save our peatland from fire

Subsurface peat fire was recognized as a key of tropical peat fire.

peatwise - peat fire characteristics -...

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