<s>
A	O
geoportal	B-General_Concept
is	O
a	O
type	O
of	O
web	O
portal	O
used	O
to	O
find	O
and	O
access	O
geographic	B-General_Concept
information	I-General_Concept
(	O
geospatial	B-General_Concept
information	I-General_Concept
)	O
and	O
associated	O
geographic	O
services	O
(	O
display	O
,	O
editing	O
,	O
analysis	O
,	O
etc	O
.	O
)	O
</s>
<s>
Geoportals	B-General_Concept
are	O
important	O
for	O
effective	O
use	O
of	O
geographic	B-Application
information	I-Application
systems	I-Application
(	O
GIS	B-Application
)	O
and	O
a	O
key	O
element	O
of	O
a	O
spatial	B-General_Concept
data	I-General_Concept
infrastructure	O
(	O
SDI	O
)	O
.	O
</s>
<s>
Geographic	B-General_Concept
information	I-General_Concept
providers	O
,	O
including	O
government	O
agencies	O
and	O
commercial	O
sources	O
,	O
use	O
geoportals	B-General_Concept
to	O
publish	O
descriptions	O
(	O
geospatial	B-General_Concept
metadata	I-General_Concept
)	O
of	O
their	O
geographic	B-General_Concept
information	I-General_Concept
.	O
</s>
<s>
Geographic	B-General_Concept
information	I-General_Concept
consumers	O
,	O
professional	O
or	O
casual	O
,	O
use	O
geoportals	B-General_Concept
to	O
search	O
and	O
access	O
the	O
information	O
they	O
need	O
.	O
</s>
<s>
Thus	O
geoportals	B-General_Concept
serve	O
an	O
increasingly	O
important	O
role	O
in	O
the	O
sharing	O
of	O
geographic	B-General_Concept
information	I-General_Concept
and	O
can	O
avoid	O
duplicated	O
efforts	O
,	O
inconsistencies	O
,	O
delays	O
,	O
confusion	O
,	O
and	O
wasted	O
resources	O
.	O
</s>
<s>
The	O
U.S.	O
National	O
Spatial	B-General_Concept
Data	I-General_Concept
Infrastructure	O
(	O
NSDI	O
)	O
,	O
started	O
in	O
1994	O
(	O
see	O
OMB	O
Circular	O
A-16	O
)	O
,	O
is	O
considered	O
the	O
earliest	O
geoportal	B-General_Concept
concept	O
.	O
</s>
<s>
The	O
U.S.	O
Federal	O
Geospatial	B-General_Concept
Data	I-General_Concept
Committee	O
(	O
FGDC	O
)	O
coordinated	O
development	O
of	O
the	O
Federal	O
Geographic	B-General_Concept
Data	I-General_Concept
Clearinghouse	O
(	O
or	O
NSDI	O
Clearinghouse	O
Network	O
)	O
,	O
the	O
first	O
large	O
geoportal	B-General_Concept
.	O
</s>
<s>
First	O
released	O
in	O
2003	O
,	O
the	O
Geospatial	B-General_Concept
One-Stop	O
(	O
GOS	O
)	O
geoportal	B-General_Concept
was	O
developed	O
as	O
part	O
of	O
a	O
U.S.	O
e-government	O
initiative	O
.	O
</s>
<s>
Unlike	O
the	O
NSDI	O
Clearinghouse	O
Network	O
,	O
GOS	O
was	O
built	O
around	O
a	O
centralized	O
metadata	O
catalog	O
database	O
,	O
with	O
an	O
architecture	O
that	O
links	O
users	O
to	O
data	O
providers	O
through	O
a	O
Web-based	O
geoportal	B-General_Concept
.	O
</s>
<s>
The	O
user	O
of	O
GOS	O
may	O
employ	O
a	O
simple	O
Web	O
browser	O
(	O
thin	O
client	O
)	O
or	O
may	O
interface	O
directly	O
with	O
a	O
GIS	B-Application
(	O
thick	O
client	O
)	O
.	O
</s>
<s>
More	O
recently	O
,	O
there	O
has	O
been	O
a	O
proliferation	O
of	O
geoportals	B-General_Concept
for	O
sharing	O
of	O
geographic	B-General_Concept
information	I-General_Concept
based	O
on	O
region	O
or	O
theme	O
.	O
</s>
<s>
Examples	O
include	O
the	O
INSPIRE	O
geoportal	B-General_Concept
(	O
Infrastructure	O
for	O
Spatial	B-General_Concept
Information	I-General_Concept
in	O
the	O
European	O
Community	O
,	O
established	O
in	O
2007	O
)	O
,	O
the	O
NatCarb	O
geoportal	B-General_Concept
,	O
which	O
provides	O
geographic	B-General_Concept
information	I-General_Concept
concerning	O
carbon	O
sequestration	O
in	O
the	O
United	O
States	O
,	O
and	O
UNSDI	O
,	O
the	O
United	O
Nations	O
Spatial	B-General_Concept
Data	I-General_Concept
Infrastructure	O
.	O
</s>
<s>
Modern	O
web-based	O
geoportals	B-General_Concept
include	O
direct	O
access	O
to	O
raw	O
data	O
in	O
multiple	O
formats	O
,	O
complete	O
metadata	O
,	O
online	O
visualization	O
tools	O
so	O
users	O
can	O
create	O
maps	O
with	O
data	O
in	O
the	O
portal	O
,	O
automated	O
provenance	O
linkages	O
across	O
users	O
,	O
datasets	O
and	O
created	O
maps	O
,	O
commenting	O
mechanisms	O
to	O
discuss	O
data	O
quality	O
and	O
interpretation	O
,	O
and	O
sharing	O
or	O
exporting	O
created	O
maps	O
in	O
various	O
formats	O
.	O
</s>
