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Posted by gwhit on May 8, 2008, 12:15 am
Please log in for more thread options wrote:
> gwhit...@gmail.com wrote:
> > I need to produce a map of our County which shows municipal boundaries
> > and with several hundred points mapped onto it. =A0As is usually the
> > case, there is no budget associated with this request. =A0I have been
> > investigating various data sources and open source GIS apps (notably
> > QGIS)... but frankly I have not been able to bring it all together...
> > there are so many file types and proprietary solutions.
>
> > Would someone help me identify the 'full set' of what's needed? =A0That
> > is, the proper file types or components and a (free) tool that will
> > display them. =A0I believe I can figure out how to produce a CSV file of=
> > the locations I need to map, which I gather will need to be converted
> > from street addresses to lat/long pairs. =A0But what, where, and how to
> > find the map image itself, and an overlay for municipal boundaries,
> > and match them... I'd very much appresiate some guidance. =A0Thanks in
> > advance. =A0 --Gary
>
> Hi Gary,
> Google should be your friend! ... there are lots of map layers available
> online!
> =A0From your IP address, it seems your are in NY, Greene County. Have a
> look here:http://www.nysgis.state.ny.us/gisdata/inventories/results.cfm?SW=
IS=3D19...
> especially entry #11
> Download the shapefile
> (https://www.nysgis.state.ny.us/secured/coop/fileserver/?DSID=3D927&file..=
.
> )
>
> Then open this file in QGis (or else), and voila!
> The freeware "GVsig" might be easier to use...http://www.gvsig.gva.es/inde=
x.php?id=3D1731&L=3D2
>
> To geocode your points, read your GIS manual:
> for QGis:http://gisalaska.com/qgis/doc/user_guide_en.pdf=A0p105, section 1=
1.4
> for GVsig:http://www.gvsig.gva.es/fileadmin/conselleria/images/Documentaci=
on/de...
> =A0 p100, section 5.8.1
>
> You could also usehttp://ofb.net/%7Eegnor/google.html=A0to extract the
> coordinates from your street address.
>
> Now, the beauty of a GIS (versus an image editor) is that your data is
> georeferenced. It means that each point or polygons has coordinates in
> it, which allows the program and the user to locate the dataset on the
> globe. You can also display several layers of data, one on top of each
> other. So, in your case, you would display the boundary, then overlay
> your point data (and any other layer such as the road network etc), and
> this will automagically create a map for you, with each item loacated at
> the correct place!
>
> Hope this help!
> Jean
Thanks SO much, Jean... That was precisely the sort of simple,
complete direction I needed. I've gotten the boundary shapefiles that
you pointed to (I do have access to that nygis data sharing coop) and
loaded them in QGIS just as you suggested. gvSIG is downloading as I
write this (and they have a native mac version!). It's Columbia
County, by the way.
I'm still a ways from any deliverable, but I'm not quite as *stuck* as
I was--and that is a breath of fresh air! Still to figure out: how to
get the layers to lay on top of one another--to be visible, so to
speak, rather than only the 'top' one. For instance, the town/city
boundaries on top of the County boundary on top of the county map
raster (with my points, once I get them in a shape file, on top of it
all)
That's all for tonight... thanks again! --Gary
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