[HOT] Database, OSM & HOT (Was: Request for information about common set of tags for HOT)

Sat May 23 12:42:42 UTC 2015

There is a fairly standardized set of tags that are used frequently.
There's no requirement that they be used, but they are common conventions
that make the data more usable. So, the *database* doesn't make sure things
are right--the *community* does. If you haven't seen it yet, many of these
common tags--possibly too many ;)--are collected on the Map Features page (
http://wiki.openstreetmap.org/wiki/Map_Features) and used in other ways
such as editor presets. Another, often fascinating, way to look at tag
usage is at Taginfo (http://taginfo.openstreetmap.org/). 125 million
building=yes features! http://taginfo.openstreetmap.org/tags/building=yes

OSM to shapefile (or database) stuff is always a pain, because of the
tabular structure that shapefile/databases expect versus the freeform
key=value structure of OSM data. So you're bound to get a certain subset of
tags, unless you do some customization. There are lots of ways to create
shapefiles--see
http://wiki.openstreetmap.org/wiki/Shapefiles#Create_your_own_shapefiles
 (or for PostGIS, see  http://wiki.openstreetmap.org/wiki/Osm2pgsql)

Tagging is sometimes chaotic, inconsistent and poorly documented, but for
the most part it keeps improving--what more can you ask for? :)

Cheers,
Brad

On Sat, May 23, 2015 at 1:52 AM, Springfield Harrison <stellargps at gmail.com>
wrote:

>  Hello Blake,
>
> Thanks for those references.  I understand the first one although it does
> certainly appear daunting.
>
> The problem I see is that the long list of attributes/keys/values that are
> specified for inclusion in the shapefile can go out of date very often as
> crowd-mappers or new projects invent new key/value tags.  Having to
> manually inspect the "other_tags" field looks like a bottleneck that could
> lead to unintended query results, most likely overlooking items that have
> new keys.  This is a long list to keep up to date and there are quite a few
> of them in your example:
>
> attributes=name,type,aeroway,amenity,admin_level,barrier,boundary,building,craft,geological,historic,land_area,landuse,leisure,man_made,military,natural,office,place,shop,sport,tourism
>
>
> Anyway, I understand what you're driving at but the process seems to be
> overly complex and not given to reliable automation.
>
> Has anyone created a GUI for this?  Your example for hand wiring all these
> INI files looks tedious and easy to screw up.  I can see that a query
> builder tool that presented all the keys and their values in pick lists
> along with the relevant operators would boost the reliability and ease the
> workload in creating these queries.
>
>         Thanks for bearing with me again, Cheers . . . . . . . . Spring
> Harrison
>
>
>
>
>
> At 22-05-2015 06:55 Friday, Blake Girardot wrote:
>
> Hi Springfield,
>
> Here is how I get useful thematic layers out OSM:
>
>
> http://wiki.openstreetmap.org/wiki/User:Bgirardot/How_To_Convert_osm_.pbf_files_to_Esri_Shapefiles
>
> And here is an example files generated through what I would guess is a
> similar process every 30 mins:
>
>  http://nepal.piensa.co/
>
> Actually, I see they use a slightly different process with the same basic
> method, and the same software for the conversion/extraction:
>
>  https://github.com/GFDRR/osm-extract
>
> (feedback on my thematic layers is always welcome, we want to create the
> most useful layers we can. Examples can be found in the wiki entry for
> Vanuatu typhoon response)
>
> cheers,
> Blake
>
>
>
> On 5/22/2015 8:26 AM, Springfield Harrison wrote:
>
> Hello John,
>
> Thanks for your patient explanation, I'm beginning to see that OSM is a
> very different flavour of GIS. At the outset, my assumption was that it
> was entirely emergency oriented. I was puzzled by the references to
> hairdressers and gymnasiums but I guess they result from a different
> process.
>
> I do think that some emergency related features such as potential
> helipads, powerline crossings, towers, cable cars, landslides, glacial
> lakes, emergency shelters and such like might be better left to those
> with experience with those types of features. They wouldn't necessarily
> need to be experienced with OSM, just familiar with identifying those
> features. I'm surprised that there is no process for identifying and
> directing the more highly qualified mappers.
>
> I had intended to help with the helipad project but quickly became
> discouraged with the less than adequate imagery and the weirdness of
> leisure = common. Merely verifying the leisure = common sites would
> probably overlook lots of other qualified sites. And how many sites
> with this tag are actually sports fields as per the original intention?
> Then, mapping existing helipads marked with H in a circle, might be
> redundant as such official sites would probably be already mapped by a
> national agency. I would recommend that potential helipads be tagged as
> aeroway = helipads_potential, verified = no. Proper assessment of
> helipads requires an oblique, 3-D view. I attempted to introduce Google
> Earth into the process but licensing fears put the kibosh on that.
>
> I found this surprising because Google Earth does have several other
> products and does make a lot of noise about community and not for profit
> mapping without any references to licensing. They appear to actively
> promote user generated files being placed into the public domain. I
> have spent some time attempting to talk to them about this but the best
> I could do was an e-mail. Will advise.
>
> Thanks again for your time on this, I'm sure you have larger fish to
> fry, Cheers . . . . . . . . Spring Harrison
>
>
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