Geography Reference
In-Depth Information
8
<
0,
x
75
x
75
40
μ
R
ðÞ¼
ð
1
Þ
,
75
<
x
115
:
1,
x
>
115
where
x
is the distance from the feature center line. The crossover point
(i.e. the point with membership value 0.5) is at 95 m from the feature center line.
Rivers and lakes
. The trees of the height of 20 m were assumed on the banks with
the uncertainty of 3 m which meant the uncertainty of
30 m in a position of the
boundary defined by the obstruction angle. The linear membership function for
these water features (W) can be defined as
8
<
x
160
0,
x
160
60
μ
W
ðÞ¼
,
160
<
x
220
ð
2
Þ
:
1,
x
>
220
where
x
is the distance from the feature boundaries. The crossover point is at
190 m.
Power lines
. The height of electricity pylons was assumed to be 30 m with the
uncertainty of 2 m which meant the uncertainty of
20 m in a position of the
boundary defined by the obstruction angle. The linear membership function for
power lines (P) can be defined as
8
<
0,
x
265
x
265
40
μ
p
ðÞ¼
,
265
<
x
305
ð
3
Þ
:
x
>
1,
305
where
x
is the distance from the feature center line. The crossover point is at
285 m.
Forests
. The height of 20 m was assumed for the trees with the uncertainty of
3 m which meant the uncertainty of
30 m in a position of the boundary defined
by the obstruction angle. The linear membership function for forests (F) can be
defined as
8
<
:
0,
x
160
x
160
60
μ
F
ðÞ¼
ð
4
Þ
,
160
<
x
220
1,
x
>
220
where
x
is the distance from the feature boundaries. The crossover point is at
190 m.
Built-up areas
. No height of this feature was assumed however the uncertainty of
100 m in a position of the feature boundary was assumed. The linear member-
ship function for built-up areas (B) can be defined as
