7 Dec
2011
7 Dec
'11
9:45 a.m.
Appropos of this entire discussion: it sounds to
me like these problems, if they are problems, are
the consequence of the 2000-09 effort to realign
TIGER. That was the major MAF-TIGER upgrade
effort of the decade. Presumably the new lines
are (a) more accurate, and (b) won't change again.
Patty Becker
At 10:29 AM 12/7/2011, you wrote:
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Were most interested in TAZ zone-level, or
place-level stats. (I cant imagine needing Block-level change statistics.)
So, we recast all the year 2000 Block polygons
as centroid points and use spatial join to
attach a consistent-over-time TAZ code and place
code (most recent jurisdictional
boundaries). Then simply roll up Blocks into TAZ totals, place totals, etc.
There are Blocks that straddle TAZ and place
boundaries just have to live with that.
(I do repeat the step above 2 or 3 times as a
quality control: I identify Block centroids
using different centroid location options (thus
moving the points around) and test to see
whether that yields multiple membership in
multiple TAZs or places. Then I go to aerial
photography and manually recode TAZ and place
membership based on rooftops assessment: which
side of the boundary line has the majority of
structures, or else the majority of land
acreage. This is an issue only in ½ % of Blocks.)
Todd Graham | Principal Forecaster
Metropolitan Council | 390 North Robert Street | Saint Paul, MN 55101
tel: 1+651-602-1322 | fax:
1+651-602-1674 | e:
<mailto:libby.starling@metc.state.mn.us>todd.graham@metc.state.mn.us
in:
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Patricia C. (Patty) Becker 248/354-6520
APB Associates/SEMCC FAX 248/354-6645
28300 Franklin Road Home 248/355-2428
Southfield, MI 48034 pbecker(a)umich.edu