International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B-YF. Istanbul 2004
4. RESULTS
4.1 Image Processing Results
For the indication of forest fire risky places, a land use and
vegetation map was prepared using Landsat TM data. The
selection of the bands that was used for classification was made
taking under consideration the spectral profile analysis.
According to the analysis, Landsat TM bands 4, 5 and 7 were
selected to make supervised classification. Standard
topographic maps were used to indicate the control areas.
Classification accuracy was determined by using 50 random
pixels. Classification results are shown in the figure 2 and 3.
The images were classified into eight classes as forestl, forest2,
forest3, non forest, sea, lake, fog and sea shore using maximum
like hood algorithm (figure 3 and 4). First, 1992 land use results
were obtained. Then, the status of the land use in 1998 was
examined. By subtraction of the two classification results, two
important changes were indicated. These were acceleration in
forest and lake areas. In spite of the fact that the classification
accuracy results were % 93.75 and % 90.26, the cloud class in
1992 image was misleading in determination of changes in
forest classes.
Figure 4. The result of 1992 Landsat image classification that
was integrated with DEM
Forest 1
Forest 2
Forest 3
Non Forest Area
Sea Shore
Lake
Sea
Fog
36
Figure 3. The result of 1998 Landsat image classification that
was integrated with DEM
Land use information is an important factor in determination of
forest fire risk. Because of this, land use classes obtained from
satellite images were converted to vector file and integrated into
GIS.
4.2 GIS results
The information system was formed in Maplnfo software
having transferred the parameters of vegetation type,
topography, distance from roads and settlements into a database
that are important in determination of forest fire risk. For the
production of the forest fire risk map, five fire rating classes are
used. These classes are formed according to slope, aspect,
vegetation type, distance from roads and settlements. Slope and
aspect image
were generated using the DEM data (Fig 5 and 6). Aspect and
slope plays a vital role in spreading of the fire. Fire travels most
rapidly up-slopes and least rapidly down-slope. Southern slopes
are more vulnerable to catching fire.