MONITORING FIRE - AFFECTED WILDLANDS IN THE MEDITERRANEAN REGION BY APPLYING A 
REMOTE SENSING AND GIS APPROACH 
Heinz Gallaun and Cliff Banninger 
Institute for Digital Image Processing, JOANNEUM RESEARCH 
Wastiangasse 6, A-8010 Graz, AUSTRIA 
Tel.: +43-316-876-757; Fax: +43-316-876-720 
Email: gallaun@pdib40.joanneum.ac.at 
KEY WORDS: GIS, Remote Sensing, Change Detection, Multitemporal, Landsat, Resource Management, 
Forest Fires, Desertification 
1. ABSTRACT: 
Wildfires are one of the major factors that initiate land degradation processes in a semi-arid environment. Landsat 
Thematic Mapper imagery acquired in the dry period are used to derive vegetation cover maps. From these vegetation 
cover maps for different acquisition dates, vegetation cover change maps are produced, which allow the assessment of 
vegetation regeneration processes. 
The prediction of the risk of desertification is based on estimates of the potential for natural regeneration and risk of soil 
erosion. By combining remote sensing, geology, and topographic information within a GIS a relative ranking of the 
desertification risk is achieved. 
The results show the usefulness of the approach for resource management at the regional and national level and for 
many needs at the local level. 
1. INTRODUCTION 
Desertification is a process with a significant detrimental 
socio-economic impact on the environment, affecting the 
planet as a whole, but giving also an immediate cause for 
concern in the Mediterranean region. There are many 
factors that contribute to or aid in desertification, ranging 
from physical, through biological, to social processes. As 
one such factor forest wild fires may initiate a 
desertification process, depending on the extent and 
severity of damage in the burnt areas, climatic 
conditions, geology, and the state of the soil. 
Land permanently degraded to desert-like conditions, 
according to UNEP documents, continues to grow at an 
annual rate of 6,000,000 hectares. In Greece and Spain 
alone 420,000 ha of forests were destroyed by wild fires 
in the year 1991. 
This paper describes parts of the work performed by the 
Institute for Digital Image Processing (DIB) at Joanneum 
Research within the EEC project entitled A G/S Decision 
Support System for the Prevention of Desertification 
Resulting from Forest Fires within the Environment 
Research Programme of the EEC, Climatology and 
Natural Hazards. The project was undertaken in 
collaboration with the Department of Electronic and 
Electrical Engineering at the University of Surrey (UoS), 
the Laboratory of Remote Sensing at the National 
Technical University of Athens (NTUA), and the Institute 
of Mediterranean Forest Ecosystems at the National 
Agricultural Research Foundation (NARF). 
240 
The project objectives were to design and develop a GIS 
decision support system for monitoring and predicting the 
recovery of burnt forest areas after a fire and provide 
information on their potential for natural regeneration, risk 
of soil erosion, and risk of desertification. The definition of 
the system's requirements was provided by NARF, in 
consultation with the other consortium partners, based 
upon the needs of resource managers in the 
Mediterranean region. 
2. STUDY AREA / GROUND TRUTH 
Four previously burnt areas in Greece, situated in the 
hilly to mountainous Pateras, Lavrio, Pendeli, and 
Varnavas regions of Attica surrounding Athens, were 
selected as test areas. Extensive forest fires have 
occurred in these areas, some areas burnt twice within a 
decade (comp. Fig. 1). The main vegetation types within 
the study areas are closed stands of Aleppo Pine (Pinus 
Halepensis), phrygana, and phrygana/maquis. 
Within the four test areas, 39 reference sites ranging 
between 1 ha and 4 ha and representative of different 
stages of regeneration after a forest fire, were selected 
by NARF for detailed measurement of plant, soil, 
geology, and physiographical features, for use in 
establishing relationships between remote sensing data 
and ground features. 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B7. Vienna 1996 
Oa To 
"o 
tt