The Regional Mainland Southeast Asian FIRE Product, 1992-1993, from JRC
Entry ID:
SAI_JRC_Asian_FIRE_Product
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Summary
Abstract:
Comparatively little is known empirically about the vegetation fire regime of Southeast Asia when viewed at larger scales. This is despite the importance of fire as an agent of regional land cover change and in modifying atmospheric chemistry. Fire is widely used in rice cultivation in Asia where 94% of the world's crop is grown [Nguyen et al., 1994]. It also has a ... high incidence within forests in tropical Asia [Hao and Liu, 1994] where it is mainly associated with shifting cultivation [McNeely et al., 1991]. As with the neo-tropics and the African tropics, Southeast Asian tropical forests are of considerable ecological and economic importance and makeup about 20% of the world's tropical forest resource [after FAO, 1993]. Information on biomass burning within the Indo-Malayan region is needed to assist in the modelling of large-scale atmospheric pollution and climate change phenomena and for regional use by landuse managers, habitat conservationists, and national and regional policy makers. Mainland Southeast Asia is the focus of the Southeast Asian fire product since it is more strongly seasonal and less humid than many parts of insular Southeast Asia [Nix, 1983] and thus both favours the use of fire as a land management tool and supports more fire-prone ecosystems [54% of forest formations are tropical seasonal forest compared to 4% within insular regions, FAO, 1993]. The mainland Southeast Asian product offers an analysis of the spatial and temporal distribution of vegetation fire in mainland Southeast Asia using AVHRR 1 km resolution data for the period of a single dry season [that chosen is from November 1992 to April 1993]. - Pre-processing: Images selected for pre-processing had [i] low cloud cover [cloud cover over land generally < 30%], [ii] a central swath position to avoid excessive distortion of pixel geometry which is pronounced towards swath extremities, and [iii] low digital corruption [dropped lines and partial line reading]. Thirty images from the available 55 fulfilled these criteria. The pre-processing rational and methodology used are given in Achard and D'Souza [1994], with the exception that that [i] channel-3 radiance was additionally converted to brightness temperature and [ii] a sixth data band is provided which is the difference between channel-3 and channel-4. Accordingly, pre-processing calibration gave channel output as summarised in Table 5.1 below. First-order geometric correction was made using calculated 'tie-points'; data was transformed to the Plate Carree [Lat/Lon] map projection and an area of interest window of 5deg 30' - 25deg 0' N, 97deg 30' - 110deg 0' E was extracted. Table: Band characteristics of AVHRR data used to derive point-fire maps Image band Band description: Radiometric units and scaling: number: Bands 1,2 AVHRR channel-1, 2 Top of atmosphere reflectances x 10 Bands 3,4,5 AVHRR channel-3, 4, 5 [Brightness temperatures - 223] x 10 Band 6 AVHRR [channel-3, 4] Brightness temperature x 10 - Processing: There are three stages in data processing, these are outlined below. [i] Geometric correction: Second-order geometric correction to within c. 1 pixel accuracy was made using user-defined ground control points. [ii] Cloud masking: Cloud cover was determined after visual inspection of the images showed that land-cloud and cloud-smoke differentiation was clearest using the algorithm {[channel-1 + channel-2] > 25% top of atmosphere reflectance and channel-5 < 288 K}. [iii] Fire algorithm derivation: Active fire detection was achieved by classi- fying images using a multi-spectral thresholding technique that used channel-3 and channel-4 brightness temperature. The thresholds of the algorithm were defined using a training-set of pixels that showed [i] saturation, or near saturation, in channel-3, but which [ii] were not saturated on consecutive days. The second criterion was to reduce false-fire detection by minimising the possibility of including semi-permanent hot pixels that saturate due to sunglint or solar heating of the ground. In addition [and especially when next-day consecutive images were not available or when cloud cover was obstructive], other features were used to identify fire and build the training-set, i.e. the spatial distribution of candidate fire pixels, their configuration, background-pixel spectral characteristics, and the presence of smoke. A new training-set was created for each image to account for temporal changes in land surface characteristic and changes in atmospheric conditions and viewing angle. The use of multi-spectral algorithms is discussed by Stuttard et al. [1995] and Justice and Dowty [1994], here the algorithm derived for each image was of the form: Step 1: Bt3 > k1 Step 2: Bt3 - Bt4 > k2 Step 3: Bt4 > k3 Where Bti is brightness temperature in channel i, k1 is fixed to 320 K [slightly below the saturation temperature of channel-3], and k2 and k3 are determined by the lower 95% confidence interval [ - 2s] of the distributions of the fire training-set radiance values for each image. If the criteria of all three steps are met then the pixel is classified as a fire. NB this image-specific approach could not be used to determine an image-dependent algorithm threshold for channel-3 since this channel's response is influenced by the saturation phenomenon of the sensor. There are two main categories of products and two subsidiary categories of products. The main products are point-fire maps [daily and daily-composite] and fire-density maps [composite]. These products are described in detail below. The subsidiary products are cloud cover [daily and daily-composite] and the source images [AVHRR pre-processed data] from which the fire and cloud maps are derived. Point-fire maps: Files are produced from sea and cloud masked AVHRR 1 km resolution images using image-specific multi-threshold fire detection algorithms. Temporal coverage: - Daily: 30 images, November 1992 to April 1993 [image dates are 10-11/11, 10-14/12, 19-21/12, 27-28/12, 30/12/1992 and 30-31/1, 1-2/2, 6-9/2, 3-6/3, 4-6/4, 16/4, 23/4/1993]. The point-fire map for 4 April 1993 is illustrated in Figure 9a. - Two-monthly: Nov/Dec 1992 [early dry season], Jan/Feb 1993 [mid dry season], Mar/Apr [late dry season]. - Six-monthly: November 1992 to April 1993 [30-image composite over the 1992/93 dry season]. Fire-density maps: Files are produced from the 30-image composite of point-fires described in Section 5.3.1 above; fire density within 25 x 25 km grid cells is plotted on a relative scale: low, medium, high and very high fire activity [categories are defined]. Temporal coverage: - A single map covers the entire 1992/93 dry season [November to April]. Users will find the active fire data product most useful if it is integrated with GIS support. A summary of the scales, land cover/land use, infrastructure, and applications that the data may be used at, integrated with, and applied to is given below. An exhaustive list of potential uses is not given here since the user-community is well aware of its own needs. * Scale: Local [e.g. national park studies], country [national policies], regional [Southeast Asian perspectives]. * Land use: Permanent agriculture, shifting cultivation, timber, plantation, grazing. * Land cover/terrain: Forest, savanna, savanna woodland, elevation, * national parks. * Infrastructure/communications: Roads, rivers, habitation. * Applications: Atmospheric chemistry, land cover change, deforestation, fire ecology, population and migration pressure.
Geographic Coverage
(Click for Interactive Map)
Spatial coordinates
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N: 25.0
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S: 5.0
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E: 110.0
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W: 97.0
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Data Set Citation
Dataset Originator/Creator:
J-M. Gregoire, P. Barbosa, E. Dwyer, H. Eva, S. Jones, B. Koffi, J.P. Malingreau
Dataset Title:
Vegetation fire research at the Monitor. Tropic. Veget. Unit: Prod. availability
Dataset Release Date:
1996
Dataset Release Place:
Joint Research Centre of the European Commission, Ispra, ITALY
Dataset Publisher:
European Commission
Data Presentation Form:
Map
Online Resource:
http://www.gvm.sai.jrc.it/fire/default.htm
Temporal Coverage
Start Date:
1992-11-11
Stop Date:
1993-04-23
Data Resolution
Latitude Resolution:
0.01 degree
Longitude Resolution:
0.01 degree
Temporal Resolution:
DAILY, Two-monthly, Six-monthly
Quality
The user is advised that this data set has not been validated with higher resolution data or by field survey. In general, the utility of the fire detection algorithms is determined by the characteristics of the training-set used to define their thresholds. It is considered that the active fire estimates provided here are conservative since a ... major consideration has been to minimise the inclusion of false-fires in the data set. This is achieved by setting a high value for the channel-3 threshold [k1] [Kaufman et al., 1990] and by excluding potential fire pixels that were saturated on consecutive days [Malingreau, 1990]. For the Southeast Asian fire product, the k1 threshold was set to 320 K [slightly below the saturation brightness temperature of the sensor]. The fire training-set may also have been biased against savanna and savanna woodland fires since their detection is more difficult than in humid, forst environments with cool background temperatures [Malingreau, 1990]. There may, therefore, be an under-sampling of fires in these warmer background environments. Users are reminded that the NOAA satellite overpasses at a local time of approximately 14:30. The sampling of fires is, therefore, biased towards those that are active during the early afternoon. 
Access Constraints
End-users external to GVM can have access to the data and make use of it in their own field of research and/or application only if they fullfill the use- constraints listed below.
Use Constraints
When the data set is derived from results already published in conferences or journals, the external user must agree with MTV on the correct form of refer- ence. If it is derived from results not yet published, the external user and GVM should agree on a co-author work.
Data Set Progress
IN WORK
Personnel
Role:
DIF AUTHOR
Phone:
+39 332 78 98 22
Fax:
+39 332 78 90 73
Email:
olivier.draily at jrc.it
Contact Address:
Global Vegetation Monitoring Unit
T.P. 440
Joint Research Centre (European Commission)
City:
Ispra (VA)
Postal Code:
I-21020
Country:
Italy
Role:
TECHNICAL CONTACT
Phone:
+39-0332-789215
Fax:
+39-0332-789073
Email:
jean-marie.gregoire at jrc.it
Contact Address:
GVM Unit - Global Vegetation Monitoring
Head of Fire Group
European Commission
Joint Research Centre
(VA)
City:
Ispra
Postal Code:
I-21020
Country:
Italy
Role:
INVESTIGATOR
Phone:
+39 332 789410
Fax:
+39 332 789073
Email:
jean-paul.malingreau at jrc.it
Contact Address:
Global Vegetation Monitoring Unit
T.P. 440
Joint Research Centre (European Commission)
City:
Ispra (VA)
Postal Code:
I-21020
Country:
Italy
Publications/References
Achard F., and D'Souza G., [1994]. Collection and Pre-Processing of NOAA-AVHRR 1 km Resolution Data for Tropical Forest Resource Assessment. TREES Series A, Technical Document No. 2, Publication of the European Commission Report EUR 16055 EN, Joint Research Centre, European Commission, Ispra, Italy. FAO, [1993]. Forest Resources Assessment 1990: Tropical ... Countries. FAO Forestry Paper 112. Food and Agriculture Organisation of the United Nations, Rome. Hao W. M., and Liu M-H., [1994]. Spatial and temporal distribution of tropical biomass burning. Global Biogeochimical Cycles, vol.8, no.4, 495-503, December 1994. Jones S., [1996]. The distribution of vegetation fire in mainland Southeast Asia: a spatio-temporal analysis of AVHRR 1 km data for the 1992/93 dry season. Publication of the European Commission, JRC Technical Note, 1996, in press. Kaufman Y.J., Tucker C.J., and Fung I., [1990]. Remote sensing of biomass burning in the tropics. Journal of Geophysical Research, 95, 9927-9939. Malingreau J.P., [1990]. The contribution of remote sensing to the global monitoring of fires in tropical and subtropical ecosystems. In Fire in the Tropical Biota [ed. J.G. Goldammer], pp. 337-370. Springer-Verlag, Berlin. McNeely J., Sayer J., Anspach P., Ng., F., Singhapant S., Nuevo C., and Van der Heide J., [1991]. Shifting cultivation. In The Conservation Atlas of Tropical Forests: Asia and the Pacific [ed. N.M. Collins, J.A. Sayer and T.C. Whitmore], pp. 30-35. IUNC. Macmillan Press Ltd, London. Nguyen B.C., Putaud J.P., Mihalopoulos N., and Bonsang B., [1994]. CH4 and CO emissions from rice straw burning in south east Asia. Environmental Monitoring and Assessment, 31, 131-137. Nix H.A., [1983]. Climate of tropical savannas. In Tropical Savannas, Ecosystems of the World 13 [ed. F. Bourliere], pp. 37-62. Elsevier Scientific Publishing Company, Amsterdam. Stuttard M., Boardman S., Ceccato P., Downey I., Flasse S., Gooding R., and Muirhead K., [1995]. Global Vegetation Fire Product. Final Report for JRC contract no. 10444-94-09-FIEP ISP GB - April 1995, p. 74 + annexes. Complete bibliographical reference: European Commission, EUR 16433 - Vegetation fire research at the Monitoring Tropical Vegetation Unit: Product availability - June 1996, J-M. Gregoire, P. Barbosa, E. Dwyer, H. Eva, S. Jones, B. Koffi, J.P. Malingreau, 1996 - 84 pp., Catalogue: CL-NA-16433-EN-C
Creation and Review Dates
Last DIF Revision Date:
2009-04-20
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