-------- Original Message --------
Subject: Re: "Natural borders"
Date: Thu, 3 Nov 2011 11:28:11 -0400
From: Michael Fry <[log in to unmask]>
To: Maps, Air Photo, GIS Forum - Map Librarianship
<[log in to unmask]>
Chris,
This sounds like a great GIS question, with one possibly major caveat.
Boundaries that aren't straight lines--coastlines, mountain ranges,
rivers, etc.--can be measured with varying degrees of "accuracy," which
is to say detail. Case in point: I just researched the length of Oman's
coastline. Most published figures, including those from State Dep't,
CIA, Columbia Gazetteer, Statesman's Yearbook, Webster's Geographical
Dictionary, and several Omani gov't sources, cite one of three figures:
* 1,700 km/1,056 mi
* 2,092 km/1,300 mi.
* 3,165 km/1,967 mi.
The variability, which I discussed with a couple nice fellows from NOAA,
has everything to do with the scale of maps/imagery used to measure said
boundaries, and how one chooses to define terms (e.g., "coastline").
None of these figures is "wrong," but some are perhaps more right than
others? ;)
Anyway, variability like this would, if I'm not nuts, do a lot to
complicate the answer to your patron's question. I'm sure you could
compile an answer with GIS, but you might want to qualify it with notes
about the scale of the data used? Or, if you have time and inclination,
do it with several data sets at several scales and provide an estimate
or range?
$.02
Good luck Thiry!
mf
--
Michael Fry
Senior Map Librarian
National Geographic Society
1145 17th St. N.W.
Washington, D.C. 20036
202.857.7098 <tel:202.857.7098>
[log in to unmask] <mailto:[log in to unmask]>
On Thu, Nov 3, 2011 at 10:45 AM, Angie Cope, American Geographical
Society Library, UW Milwaukee <[log in to unmask] <mailto:[log in to unmask]>> wrote:
------- Original Message --------
Subject: "Natural borders"
Date: Thu, 3 Nov 2011 08:29:20 -0600
From: Christopher Thiry <[log in to unmask] <mailto:[log in to unmask]>>
To: [log in to unmask] <mailto:[log in to unmask]>
<[log in to unmask] <mailto:[log in to unmask]>>, GISCO
<[log in to unmask] <mailto:[log in to unmask]>>
All,
I need help answering this email I received from a patron. Thanks in
advance.
Christopher J.J.Thiry
Map Librarian
Colorado School of Mines
1400 Illinois
Golden, CO 80401
p. 303-273-3697 <tel:303-273-3697>
f. 303-273-3199 <tel:303-273-3199>
[log in to unmask] <mailto:[log in to unmask]> <mailto:[log in to unmask]
<mailto:[log in to unmask]>>
http://library.mines.edu/
------------------------------__------------------------------__------------
*From:* Ashley Pryor
*Sent:* Wednesday, November 02, 2011 5:01 PM
*To:* Christopher Thiry
*Subject:* Map Question
Christopher,
I am wondering if you can assist me to compile a statistic for %
“natural border” for all countries in the Middle East. Natural borders
for instance would be coastlines, mountain ranges, large rivers,
etc. Of
course sometimes borders are built along these natural boundaries, and
sometimes they are arbitrary of natural boundaries. I am wondering if
you have a set of maps that clearly show natural boundaries against
national borders, or better yet, already have access to a data set that
has already compiled the percent national border that follows a natural
boundary. If you have such a data set, any or all regions would be
beneficial to my research. If you do not know of any particular data
set, perhaps you have some time to meet with me and let me know which
map sets would be most helpful in compiling such a statistic.
Please let me know if you have any availability in the next couple of
days to perhaps discuss.
Thanks so much for your time and your work.
Regards,
Ashley Pryor
|
