<s>
In	O
geographic	B-Application
information	I-Application
system	I-Application
(	O
GIS	B-Application
)	O
,	O
change	B-Application
detection	I-Application
is	O
a	O
process	O
that	O
measures	O
how	O
the	O
attributes	B-General_Concept
of	O
a	O
particular	O
area	O
have	O
changed	O
between	O
two	O
or	O
more	O
time	O
periods	O
.	O
</s>
<s>
Change	B-Application
detection	I-Application
often	O
involves	O
comparing	O
aerial	O
photographs	O
or	O
satellite	O
imagery	O
of	O
the	O
area	O
taken	O
at	O
different	O
times	O
.	O
</s>
<s>
Change	B-Application
detection	I-Application
has	O
been	O
widely	O
used	O
to	O
assess	O
shifting	O
cultivation	O
,	O
deforestation	B-Application
,	O
urban	O
growth	O
,	O
impact	O
of	O
natural	O
disasters	O
like	O
tsunamis	O
,	O
earthquakes	O
,	O
and	O
use/land	O
cover	O
changes	O
etc	O
.	O
</s>
