[OHM] Mapping the NY Metro Region's Historic Wetlands

Fri Sep 25 20:16:43 UTC 2015

Hello listers,
I recently subbed to this list and Sanjay's OP got me to weigh in here for
the first time...

I'm one of the organizers of TeachOSM[1] and an administrator for
TeachOSM's instance of the Tasking Manager[2]. Happy to have you use our TM
to support this project. Please shoot me a note offline and I'll help you
get started.

By way of introduction, I'm a long time contributor to OpenStreetMap,
organize events in WashDC with MappingDC, former US board OSM-US, and
MaptimeDC organizer. Happy to help organize an OHM-based project for a DC
Maptime event.

This is an awesome project and I'd be happy to see if there's a way to get
students/young adults interested in, and organized to contribute.

Steven Johnson

[1] http://teachosm.org
[2] http://tasks.teachosm.org

-- SEJ
-- twitter: @geomantic
-- skype: sejohnson8

There are two types of people in the world. Those that can extrapolate from
incomplete data.

On Fri, Sep 25, 2015 at 3:48 PM, Sanjay Seth <sanjay at rpa.org> wrote:

> Jerry –
>
> Thanks for the quick and detailed reply. Watched your video that
> referenced NYPL’s Map Warper before posting here. And right after I sent
> this message to OHM, I sent a message to MapTime organizers. Will see where
> it goes!
>
> The NOAA maps are in Clarke 1661 projections and, while they have points
> that could be used to rectify, I have been georeferencing the maps in
> ArcGIS. Is there a benefit to doing the rectification in Map Warper vs
> ArcGIS, as far as the OHM/OSM workflow? It may be easier to share the
> georeferenced maps after the fact, than georeferencing natural features in
> a browser. (NOAA maps
> <http://nosimagery.noaa.gov/images/shoreline_surveys/survey_scans/NOAA_Shoreline_Survey_Scans.html>
> )
>
> I really like the OSM Task Manager that HOTOSM has running. It would be
> nice to be able to feed this into that process and chunk out the tasks to
> the various universities in the region that would be interested in taking
> on a part of it. Not sure I have the technical chops to get it up and
> running, but it sounds like a good way to break this up.
>
> Semi-automated tracing sounds interesting, though the maps are not uniform
> in style. What are some good resources to look into further? I have stayed
> away from ArcGIS’s automated tracing, as it is better for roads or very
> obviously defined polygons. The wetlands are signified not by shading or
> stroke, but by a kind of grassy icon, which may make automation less
> tenable.
>
> David – I’ve checked that source, but I need a rather uniform data series
> that covers a 31-county region as early as possible. Thanks for the tip,
> though.
>
> Really appreciate the replies, as I start exploring how to open up this
> process. Would love to have a regional historic wetland map available to
> the planning community that extends earlier than 1900.
>
> Best,
> Sanjay
>
> *—*
>
> *Sanjay Seth* | Research Analyst
>
> Regional Plan Association
>
> (917) 546-4327 | rpa.org
>
> From: SK53 <sk53.osm at gmail.com>
> Date: Fri, 25 Sep 2015 15:26:47 -0400
> To: Sanjay Seth <sanjay at rpa.org>
> Cc: "historic at openstreetmap.org" <historic at openstreetmap.org>
> Subject: Re: [OHM] Mapping the NY Metro Region's Historic Wetlands
>
> Hi Sanjay,
>
> A timely query. We were discussing only on Tuesday about the use-cases for
> mapping historical ecological data. This example of course reflects lots of
> them (wetlands as buffers in extreme events; as components of water
> quality; and in some parts of the world sources of disease).
>
> Again we discussed on Tuesday ideas for getting communities involved. I
> have been thinking about this over the past few days and realise that the
> scheme used by Humanitarian mappers, Missing Maps, and the smaller
> get-togethers under the MapTIme banner both represent models for getting a
> group of people to map specific things allowing straightforward training,
> coaching & mentoring. Another, rather different, approach is the Irish
> Townland mapping project, which involves rectifying 1:25k maps covering
> Ireland (80,000+ sq km) and drawing 60,000 small administrative units from
> them.
>
> Currently the OHM community is quite small and many of us have multiple
> commitments to existing projects and related OSM activities (for instance I
> am doing some specific things in the context of the townlands project), so
> I don't think we are a great pool of tracers. The much larger OSM
> communities do have many more people who are looking for such challenges.
> I'd perhaps start by seeing if MapTime New York
> <http://www.meetup.com/Maptime-NYC/> might be interested in giving you a
> slot.
>
> Now for some of the technical problems/issues:
>
>    - OHM requires that each tagged object natural=wetland is also marked
>    with a start_date & end_date.
>    - It is generally valuable to use a tag which identifies the apparent
>    as_of date of the wetland (i.e., based on underlying map), this makes
>    querying easier). This also makes it easier to filter data in some editors.
>    - It is easier to map something multiple times in different time
>    periods rather than try & reconcile an object across from many source maps.
>    (At least this is true until one has lots of such things).
>    - Coastlines may create problems. This is because of the OSM way of
>    handling coastlines is inelegant. I do have some ideas about how to
>    approach this, but haven't taken them forward yet: the coastline of the
>    River Plate changed dramatically in the late 19th C so affecting stuff I
>    have done with Buenos Aires).
>    - Use meta tags (source etc.) copiously; they will be the only
>    evidence of someone's interpretation of the sources. Ultimately other info
>    like photos, paintings and documentary evidence may need to be incorporated.
>
> Use of any of the Map Warper websites (NYPL, MapWarper & WikiMedia) for
> rectification would ensure that warped maps are readily available in the
> editors, and following the Townlands model can also be crowd-sourced.
>
> It may also be worth looking at semi-automated tracing if the map quality
> permits such an approach.
>
> HTH,
>
> Jerry Clough
>
>
>
>
> On 25 September 2015 at 19:43, Sanjay Seth <sanjay at rpa.org> wrote:
>
>> Dear OHM Community –
>>
>> I hope you are all doing well. I’m a researcher at an urban policy
>> think-tank based in NYC. We are looking at long-term coastal adaptation
>> strategies –  and are working to map out the NY metropolitan region’s
>> historic wetlands, which we will use (in addition to projected future
>> wetlands) to inform those strategies.
>>
>> I’m new to the OHM community, but would like to gauge the interest in
>> taking this on together as a group tracing effort. I have hundreds of
>> historic maps from NOAA, starting from 1830’s onward, that would be
>> relatively straightforward to trace, once they were georeferenced. We’re in
>> the process of georefererencing the lot right now. I just don’t have the
>> people-power to trace out thousands of wetlands on my own.
>>
>> If this sounds like a project you are interested in – or want to just
>> hear more about – let me know. Thanks and feel free to get in touch at
>> sanjay at rpa.org or (917) 546-4327.
>>
>> Best wishes,
>> Sanjay
>>
>> *—*
>>
>> *Sanjay Seth* | Research Analyst
>>
>> Regional Plan Association
>>
>> (917) 546-4327 | rpa.org
>>
>> _______________________________________________
>> Historic mailing list
>> Historic at openstreetmap.org
>> https://lists.openstreetmap.org/listinfo/historic
>>
>>
>
>
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