[Talk-us-massachusetts] Some observations and preliminary stats on MassGIS address import
Alan & Ruth Bragg
alan.ruth.bragg at gmail.com
Tue Jul 17 20:57:55 UTC 2018
Nice work Yury, I'd love to see those stats for just my town of Bedford.
You've inspired me to download qgis.
I've downloaded the address point shp file for Bedford where I have already
assigned addresses. I've noticed a very good match.
One very useful field is *POINT_TYPE=ABC which identifies new buildings
under construction. I was able to add 49 new buildings as
building=construction nodes. A few were already visible in the "mapbox
satellite" imagery so I was able to add the polygons.*
How can I bump what I've already mapped against the massgis address point
file. I want to bump all OSM building=*, addr:housenumber, addr:street
against the massgis Bedford AddressPts_M023.shp ADDR_NUM & STREETNAME. I
don't think lat/long does not have to be matched, I'll be able to resolve
the differences.
A visual scan of the data overlay-ed on the osm carto imagery turned up
several building where the addresses have changed. For example, a teardown
on a corner lot was re-built facing the other street and givene a new
address.
Alan
On Tue, Jul 17, 2018 at 12:57 PM Yury Yatsynovich <
yury.yatsynovich at gmail.com> wrote:
> Thanks for creating the wiki page, Angela!
>
> I did some simple spatial joins of MassGIS address points with existing
> buildings without addresses (either house number or street name missing)
> using python (geopandas and osmnx). Here are some stats from such joins by
> counties:
>
> County OSM buildings w/o addresses MassGIS points Matched
> points 1-to-1 matches Share of matched points Share of 1-to-1
> matches
> Barnstable 188370 192619 157235 121330 0.82 0.77
> Berkshire 89520 79138 62324 39290 0.79 0.63
> Bristol 233590 284883 247625 112776 0.87 0.46
> Dukes 23647 20330 13639 11236 0.67 0.82
> Essex 268122 379036 328679 147073 0.87 0.45
> Franklin 50091 40853 31336 18146 0.77 0.58
> Hampden 206111 225352 198221 100958 0.88 0.51
> Hampshire 78709 73675 60417 34122 0.82 0.56
> Middlesex 429556 779421 594647 219696 0.76 0.37
> Nantucket 14048 12963 8408 6445 0.65 0.77
> Norfolk 361719 337260 302017 147594 0.90 0.49
> Plymouth 233374 244200 207421 134116 0.85 0.65
> Suffolk 118763 457611 426855 36796 0.93 0.09
> Worcester 383670 407001 347611 173147 0.85 0.50
> TOTAL 2679290 3534342 2986435 1302725 0.84 0.44
>
> Most of the address points (84%) lie within boundaries of buildings w/o
> addresses, almost half of which (44%) are unique address point within the
> corresponding buildings.
>
> For those 1-to-1 matches the address info can be added directly to the
> buildings. For the many-to-1 matches (several addresses within one
> building) the options are either creating separate address points within a
> building or combining addresses of all such points and adding it to the
> building (e.g. addr:housenumber = 11,13,15 as suggested in
> https://wiki.openstreetmap.org/wiki/Addresses#Buildings_with_multiple_house_numbers).
> It seems that the second approach has been used for the existing addresses
> in Malden and Boston. If points in the many-to-1 matches have different
> street names then adding separate address points seems to me the only
> solution.
>
> Having visualized the data in QGIS I've noticed couple of issues:
> 1) some points lie outside, yet, very close to a building so that it is
> unambiguous to which building they belong. Maybe creating a small buffer
> (5-10m) around such points and merging them with unique buildings that
> these buffers intersect can help match them.
>
> 2) some points, as it was mentioned in previous messages, are assigned to
> parcels. E.g. there are many cases when a group of buildings (a house and,
> say, barns) have an address point next to them. It could be possible to
> identify a house among those building manually and add the address only to
> it, yet, as there might be several thousands of such cases, it can be very
> time consuming. So, for parcels I would suggest simply adding an address
> point in the middle of a parcel (as it is placed in MassGIS) without
> identifying the exact building to which the address belongs.
>
> --
> Yury Yatsynovich
> _______________________________________________
> Talk-us-massachusetts mailing list
> Talk-us-massachusetts at openstreetmap.org
> https://lists.openstreetmap.org/listinfo/talk-us-massachusetts
>
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