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

[SK53]

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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