[UW-GIS-L] how the parcel records are visualized in gis shape
lwrogers at u.washington.edu
Sun Jul 6 21:44:01 PDT 2008
While not desirable this is very common. There can be many reasons:
- a particular parcel is not taxed for one reason or another so the assessors don't bother to maintain any attributes with the polygons
- the geometry data and the assessor data were exported on different dates, King County updates their data daily
- the export process and resulting data does not faithfully represent the complex databases that assessors maintain so occasionally things like condos or real property like mobile homes no longer relate to one another
- "segmentations": an big parcel becomes many small ones and the original parcel number is gone. The polygons got updated but the attributes haven't yet, perhaps two different county departments handle the workload
Remember, you are not using the King County assessors data for anything even remotely close to what it was designed for so you just have to take what you can get. The only time that assessor's data has to be right is when they send out the revaluation notices each winter. The rest of the year is spent getting ready for the next years notices...
From: uw-gis-l-bounces at mailman1.u.washington.edu [mailto:uw-gis-l-bounces at mailman1.u.washington.edu] On Behalf Of Jie Gao
Sent: Sunday, July 06, 2008 6:39 PM
To: uw-gis-l at u.washington.edu
Cc: gaoj at u.washington.edu
Subject: [UW-GIS-L] how the parcel records are visualized in gis shape file?
I have a question on how the parcel records are visualized as gis shape file.
more specifically, i encountered following strange situation:
--(1) i download parcel layer (shape file) from Wagda. As usual, this shape file has a dbf table (attribute table) associated to it.
---(2) I also download EXTR_Parcel table from Accessor's website.
-- (3). In theory, tables from step (1) and (2) should be the same.
HOWEVER, i found some records in the EXTR_Parcel table (from accessor's website) do not match the the dbf table associated with the shape file.
Parcel record with major field=620850, minor field=0000 , DOES EXIST in the "EXTR_Parcel" table
However, when i was about to visualize this parcel in GIS (by using the parcel layer i downloaded from Wagda), i found that, the dbf table of the parcel shape file (from Wagda) DOES NOT contain any parcel record with major field=620850 at all !!!
Similar cases are: major field=679130; major field=639165; similar cases are around 120 cases.
Any Ideas on how could this ever happen? -- that is, how come some parcel recordes in EXTR_Parcel table, with explicite major and minor fields, do not have any correponding recordes in the dbf table of the Parcel shape file?? where have those parcels gone on the map then?
any input would be greatly appreciated !!
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