Use of Satellite Images for Forest Fires in Area Determination and Monitoring

Mülayim GÜRE

Çanakkale Onsekizmart Üniversitesi, Graduate School of Science and Engineering,

Chair for Physics, Çanakkale_TURKEY mgure@comu.edu.tr

Mehmet Emin ÖZEL Çağ Üniversitesi,

Department of Mathematics and Computer Science, Tarsus- Mersin TURKEY me_ozel@hotmail.com

H. Hülya YILDIRIM Kocaeli Üniversityesi, Faculty of Engineering,

Department of Computer Engineering, Đzmit-Kocaeli _TURKEY hulya.yildirim@kou.edu.tr

Muzaffer ÖZDEMĐR Çanakkale Onsekizmart Üniversitesi, Education Faculty, Department of Computer and Educational Technologies,

Çanakkale-TURKEY mozdemir@comu.edu.tr

Abstract:-----In Mediterranean climate regions, forest fires are quite common in summer months due to increases in air

temperature. Reforestation of fire areas are a constitutional

obligation in Turkey. Identification as well as the follow-up

rehabilitation efforts can be carried out by remote sensing

techniques in economic and practical ways.

In the present study, the images from LANDSAT and

ASTER satellites were used in the determination of areal

extentions and levels of damages due to recent forest fires in

October 2008 in Çanakkale Province of Turkey. Our findings

are compared with the official forest fire records by Çanakkale

Forest Administration Office. Potential use of satellite images

and related image processing and GIS techniques in the past

and present forest fire identification and rehabilitation efforts

are discussed and their possible use in the application of recent

forest law amendments (known as 2B) are evaluated.

Key words: Satellite images, image processing, forest fires and

satellite data, forest fire monitoring and rehabilitation

I. INTRODUCTION

In the world, about 5 billion hectares of forests are damaged due to forest fires, every year. In the Mediterranean countries (i.e., Greece, Italy, Spain, France, Portugal), about 500.000 hectares of forest area were harmed by fires in a year. In Turkey, such burnt areas are more than 20.000 hectares per year on the average. In every forest fire, excess carbondioxide production and oxygen -consumption, extinction of flora and fauna and important human life loses are encountered [2]. Since 1937, there have been 68214 registered forest fires up to now (about 1000 per year) and a total 1,5 million hectares of forest areas were damaged by these fires, In Turkey [1].

This study was supported by ÇOMU BAP 2008/49

In Çanakkale Province, forest fire risks increase substantially in the summer months. As the causes of forest fires, it is reported that, about 35 % of fires were started on purpose and only 3 %, thunderbolt and other natural causes and 48 % of unknown reasons [1]. Rehabilitation and reforestation of burnt areas are a constituioanl obligation in Turkey.

Today, developments in satellite data acquisition

techniques and information technologies provide new opportunities for forest fire mitigations and follow up monitoring and rehabilitation efforts economically.

In this study, we provide an example of such an

evaluation and monitoring by satellite imaging and related information technologies. Two recent forest fire areas were identified and damage assessments were attempted. We compared results of these efforts with the local forest fire administration (Çanakkale Province Forest Management) records at the end.

II- STUDY AREA AND THE DATA

Our study area is within Çanakkale Province located in the NW of Turkey, We will concentrate 2 recent fire events recoded in these locatıons. In Fig. 1 a amp of forest area distribution in Turkey together with the location of Çanakkale Province and the frames of satellite images used for the present analysis are shown.

Fig 1 (a)

978-1-4244-3628-6/09/$25.00 ©2009 IEEE 27

Fig 1 (b)

Fig. 1. (a) Map of a forest areas in Turkey (green) and the location of

present study area (red square) [1, 4]; (b) detailed positions of satellite images within Çanakkale Province.

This fire has started on 18.06.2008, on the European side

of the Çanakkale Strait and was extinguished only after 3 days of burning on 21.06.2008. According to ÇFMO, a total of 324 hectares of forest area were burned and the total economical loss was estimated to be 1.8Million TL (MTL) or about 1.2 M $ [5]. Forest fire area is shown in Fig 2, together with a photo from the reghion after the fire.

(1) Eceabat County (Yalova Village) Forest Fire

For these areas, the data from LANDSAT-5 TM dated 22-8-2007 (large square in Fig 1b) and from ASTER dated 4-11-2008 (small squares in Fig 1b) are used. Besides them, some maps, tabular data about the fires and some forest canopy information from Çanakkale Forest Management Office (ÇFMO) were available for comparison and more detailed analysis.

This fire has started on 18.06.2008, on the European

side of the Çanakkale Strait and was extinguished only after 3 days of burning on 21.06.2008. According to ÇFMO, a total of 324 hectares of forest area were burned and the total economical loss was estimated to be 1.8Million TL (MTL) or about 1.2 M $[5]. Forest fire area is shown in Fig 2, together with a photo from the reghion after the fire.

Fig. 2 (a) LANDSAT-5 TM

Fig. 2 (b) ASTER

Fig.2 (c) Photo from the area[7]

Fig. 2: Eceabat County (Yalova Village) Forest Fire Area: (a) Before

the fire (LANDSAT- 5 TM, bands 5,4,2 , dated 22 August 2007) (b) After the fire (ASTER data dated 04 Dec.2008). Burnt region starting from the sea side is fully cleared. (c) A view from the area, by a reconnaissance plane : burnt area in forefront where forest roads are now clean.

(2) Çanakkale-Güzelyalı (Intepe Municipality) Forest

Fire

This fire had started on 30 July 2008, and was fully estinguished out on 02 August 2008. Total of area about 1464 hectares were lost to the fire. Total economical

1

2

28

losses estimated by ÇFMO were about 5.3 MTL (or ~3.6 M$) [6].

Fig.3 (a) LANDSAT-5 TM Fig. 3 (b) ASTER

Fig. 3 (c) Plane photo

Fig. (d) Plane photo

Fig. 3: (a). Çanakkale-Güzelyalı (Đntepe Municipality) forest fire areas (a) LANDSAT-5 TM (5,4,2), on 22 August 2007, 12 months before the fıre (b) ASTER, on Dec. 4, 2008, about 1 month after the fire. (c) and (d): Views from the reconnoisence plane, of the fire area[7]

This fire has started on 18.06.2008, on the European side of the Çanakkale Strait and was extinguished only after 3 days of burning on 21.06.2008. According to ÇFMO, a total of 324 hectares of forest area were burned and the total economical loss was estimated to be 1.8Million TL (MTL) or about 1.2 M $[5]. Forest fire area is shown in Fig 2, together with a photo from the reghion after the fire.

III. MATERIAL AND METHODS

Once the areal extent of the fires were determined from the after-fire image from ASTER, various analysis techniques were applied the region within the boundaries. For this purpose, the following procedures were followed:

(a) Frequency distribution of pixel reflection

values from the fire area before and after the event.

(b) Frequency distribution of vegetation index values from the fire area before and after the event.

(c) Unsupervised classification of the fire area before and after the fire.

The vegetation index values were defined according to the following: General definition of vegetation index:

NDVI =(IR-R) / (IR+R) (1)

Çanakkale Strait

Güzelyalı

29

Definition of vegetation index for LANDSAT:

NDVI=(Band4-Band3) / (Band4+Band3) (2 )

Definition of vegetation index for ASTER:

NDVI=(Band3-Band2) / (Band3+Band2) (3 )

IV. RESULTS

We will only concentrate on the frequency distribution of vegetation index (VI) values before and after the fire. However, since ‘before’ and ‘after-fire’ distributions come from different satellites with a slightly varying color response functions, a comparison of these distributions need further care. Since VI band definitions of LANDSAT and ASTER are quite similar to each other, we can use the direct distributions for a preliminary estimation.

In Fig 4 we see the maps and distribution functions for Intepe Forest Fire (IFF) while Fig 5 repeats the same for the Eceabat Forest Fire (EFF).

In Fig 4c,d are compared the vegetation indices of forest fire area for Eceabat (Yalova Village) event. It indicates the noticible differences between vegetation index mean values: <VI (before fire)> = 0.42 +/-0.04 (4)

<VI (after fire)> = -0.13 +/-0.02 (5)

This shows that VI indeed a good measure of fire area

mapping. The resultant map for the area after the fire for VI variation in the region for VI>0 and VI<0 values is given as Fig 5e. Area estimation by VI is summarized in the Table of Fig 5f. Here, our forest fire area estimation (345 ha) is in good agreement with the official ÇFMO value (324 ha).

Fig. 4 (a) Yalova: Before Fire, Landsat (543), 2007

Fig. 4 (b)Yalova: After Fire, Aster (132) 2008

Fig. 4 (c) Yalova NVDI before fire

Fig 4 (d) Yalova NVDI after fire

30

Fig. 4 (e)Yalova: NVDI, after fire classification

Figure-4a,b,c,d,e,f: Yalova- Eceabat Forest Fire

Assesment

Fig. 5. (a) Đntepe: Before Fire Landsat (543), 2007

Fig.5 (b) Đntepe: After Fire Aster (132) 2008

Fig.5 (c) Intepe NVDI before fire

Fig. 5 (d) Đntepe NVDI after fire

Fig. 5(e) Đntepe NVDI after fire classified by clustering

Fig. 4 (f) Yalova Forest Fire Area Estimation

Classes Area(ha) ÇFMO fire area estimation (ha)

Unburned (Agricultural land and others) (VI>0)

187.174 -------

Forest fire area (VI<0)

345.53 324.0

31

Figure-5a,b,c,d,e,f: Intepe Forest Fire Assesment

In Fig 5, the same analysis is repeated for the Intepe

forest fire area with similar results. In both cases, ÇFMO estimations are about 5% higher than present estimations [5,6,7].

V. DISCUSSION

(1) Local Çanakkale Forest Management Office (ÇFMO)

estimation of the fire areas were systematically lower than our image classification results by about 5%. This could be due to subjective evaluation of such areas by the Forest Management Office experts.

(2) Satellite images allow us to define the boundaries of fire

areas and estimate the extent of fire areas in a quick and economic way. Since burnt area estimations by remote sensing and in-situ measurements by ÇFMO are quite in agreement, we can also reliably estimate the agriculture areas within the forest boundaries by remote sensing.

(3) For true area estimations and reliable assesnents, a 3D-

modeling of the forest region would be needed. Then, the contribution of topography to the area estimations as well as fire damage costs (in terms of tree numbers and wood yields) could more reliably be carried out by remote sensing and image processing techniques.

(4) It is interesting to note that, most fires in the region

(including the 2 we have concentrated) cover areas which have long sea coasts. Espectialy the more recent fire near Đntepe village has occurred in a very valuable area due to its magnificent ‘views’ of Gallipoli National Historical Park and the Çanakkale Strait. This definitely raises the suspicion that its true cause may not be the heat of the summer months, but, human intervention to clear the region for further ‘luxary’ housing. Its reforestation (as the forest laws and Constiturion of Republic of Turkey requires) will be a new test for the Ministry of Forestry for their intentions in the recent new forest fire law amendments to the ‘clause 2B regulations’ [3]. Suspicion is that the Ministry or Central Government, under the strong pressure of ‘building’ and tourism lobbies in the country, may have to stop the reforestation of such lands, claiming they are no more

fulfilling the official definition of a forest, after the fires. If reforestation is successfuly carried out and completed, this will also distract further intentional forest fires for the purpose of opening new residential areas.

REFERENCES

[1]- Erkan, A. “Forest Fire and Meteorology”, website on March 23 2009, at http://www.meteoroloji.gov.tr/2006/arastirma/files/105_ormanyan01.jpg

[2]- TC Ministry of Environment and Forestry website on March 23, 2009, at http://www.cevreorman.gov.tr/yangin_semp.htm

[3]-Turkish Republic Official Gazette (Resmi Gazete), dated 03.07.2004 and numbered 25551 and dated 17.06.2004 and numbered 5192 on the new Forest Law including new rules on 2B clause of earlier Forest Law.

[4]- Forest Inventory Maping: http://www.ogm.gov.tr/maps/turkiye/ormanharita.jpg on March 23, 2009

[5]- Balamur, T. Aydin N, “Çanakkale Forest Management Office (ÇFMO)- fire registry for August 04, 2008

[6]- Sezek A., Sözen M. E., Aydemir Z. Çanakkale “Forest Management Office (ÇFMO)- fire registry for Dec. 23, 2008

[7]- Yavuz V., 2009, (ÇFMO Director), private communication.

Fig.5 (f) Intepe Forest Fire Area Estimation

Classes Area(ha) ÇFMO fire area estimation (ha)

Unburned (Agricultural land and others) (VI>0)

532,085 -------

Forest fire area (VI<0)

1407,53 1464,4

32