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International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXX V, Part B7. Istanbul 2004 
LEGAL' uses operations sentences with grammatical rules to 
generate a map, in raster format, with the principals changes 
occurred in those polygons in the period between 1987 to 2002, 
in the study area. The operations sequences using the thematic 
classes implanted with LEGAL are shown bellow: 
{ 
// Defining. variables and categories 
Thematic deforested area 2002 ("seismic 02"), deforested area 
1987 ("seismic 07"), 
Results ("crossing results 1"); 
//Recovering plans 
deforested area 2002=Recover (Name = "seismic 02"); 
deforested area 1987= Recover (Name = "seismic_87"); 
// Creating new information plan 
results-New(Name-"crossing results2", 
Resolution X=30, Resolution Y=30, 
Scale=60000); 
//Defining the relations among the classes 
results = Attribute (Category END = "crossing_results") 
J 
i 
"GG87N02": (deforested area 1987.Class == "generic glades" 
&& ! (deforested area 2002.Class == "generic glades")), 
"GG87E02": (deforested area 1987.Class — "generic glades" 
&& deforested area 2002.Class == "generic glades"), 
"GG02N87": (deforested area 2002.Class == "generic glades" 
&& ! (deforested area 1987.Class == "generic glades")), 
"SG87N02": (deforested area 1987.Class == "seismic_87" 
&& ! (deforested area 2002.Class == "seismic_02")), 
"SG87E02": (deforested area 1987.Class == "seismic 87" && 
deforested area 2002.Class — "seismic 02"), 
"SG02N87":( deforested area 2002.Classe == "seismic_02" && 
! (deforested area 1987.Class == "seismic 87")) 
E 
Being: 
GG87N02: generic glades existing in 1987 but not in 2002; 
6687E02: generic glades existing in 1987 and 2002; 
GG02N87: generic glades existing in 2002 but not in 1987: 
SG87N02: seismic glades existing in 1987 but not in 2002: 
SG87E02: seismic glades existing in 1987 and 2002: 
SG02N87: seismic glades existing in 2002 but not in 1987. 
Measuring Classes 
Using the information plans with vectorial files of the 
deforested polygons for each scene, it was possible to calculate 
the area in Knr of each class for 1987 and 2002 years in the 
study area, so allowing to measure the principals 
transformations occurred over petroleum exploration. 
Kernel's density estimator 
The algorithm Kernel's density estimator carries out an 
estimative of the points or areas patterns’. Using the information 
plans with vectorial files of deforested polygons for each scene, 
it generated a new information plan, in raster format, plotting 
possible lines of seismic survey in the study area. 
  
More details about LEGAL language see in CAMARA er 
alli (1996). 
More details about Kernel's density estimator see in 
CAMARA et alli (1996). 
371 
3.0 Achieved Results 
3.1 Spatial Anaysis — Algebra of Maps 
After the application of operations sentences in LEGAL 
language, it generated a new information plan, in raster format, 
wherby it is possible to visualize the principals changes 
occurred in terms of deforested areas from classes. that have 
already been defined: GG87N02, GG87E02: GG02N87; 
SG87N02; SG87E02 and SG02N87 that were plotted. 
The figure 5 shows the results of maps algebra application. 
  
  
« ~ 3 * 
$087E02 te ct, 
BE ccozney s" wt ta : . 
a », € "^n e 
-* T = 
GG87E02 98. 
a E - ls a um 
1:2 GG87NO2 4 
377. * . 
“ e € 
+ ¥ Eye ow « 
LU ^ wy * $ . 
> * : ®* « . 
=» “ & s, te 
€ » à - i x * a 
* à , a 
= * * * * 
' % s 
Figure 5 — Information plan resulted of the algebra of maps, in 
raster format, with principals changes occurred in terms of 
deforested areas in the study area 
3.2 Spatial Anaysis — Measures classes 
The Table 1 presents the results, in terms of area in Kr, of 
principals thematic classes of deforested polygons obtained 
from digital data input. 
| Area in 1987 (Km!) 
Class | Area in 2002 (Km?) 
Generic Glades 13,87 | 2117 
Seismic glades 1,62 | 2,03 
Another 1,10 | 2,10 
activities —— | 
Table 1 — Area (Km?) of deforested polygons: 1987 to 2002 
3.2 Spatial Anaysis — Measures class 
The Table 2 presents the results, in terms of area in Sof 
principals thematic classes generated by algebra of maps. 
Glass esee: . Area (Km) — 
SONS uat NS 
GG87E02 21,17 
GG02N87 15,30 
_SG87N02 — o MR. 
SG87E02 2,63 
SG02N87 2,10 
Table 2 — Thematic classes areas ( Knr)