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open-city / chicago-river-sewage

Is there sewage in the Chicago River?
http://istheresewageinthechicagoriver.com
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chicago riverways geojson #6

Closed derekeder closed 10 years ago

derekeder commented 10 years ago

We'd like to make this map in geojson:

MWRD waterways

@fgregg and @evz were able to extract waterways from OSM and dump it to this file: https://github.com/open-city/chicago-river-sewage/blob/master/data/MWRD_Rivers.geojson

However, there are more rivers there than we care about and the file is 7mb+.

@iandees & @stevevance, know a good way to clean this up?

Related to #5

fgregg commented 10 years ago

@evz and I talked about this. It will be pretty easy to prune the data in QGIS. Let's map the overflow points together with the data and we prune.

On Wed, Dec 18, 2013 at 11:07 AM, Derek Eder notifications@github.comwrote:

We'd like to make this map in geojson:

[image: MWRD waterways]https://github-camo.global.ssl.fastly.net/502fde80279d0f5fef19bab53fcef290fe4fe5c4/687474703a2f2f617070732e6d7772642e6f72672f43534f2f696d616765732f776174657277617973656374696f6e712e676966

@fgregg https://github.com/fgregg and @evz https://github.com/evzwere able to extract waterways from OSM and dump it to this file: https://github.com/open-city/chicago-river-sewage/blob/master/data/MWRD_Rivers.geojson

However, there are more rivers there than we care about and the file is 7mb+.

@iandees https://github.com/iandees & @stevevancehttps://github.com/stevevance, know a good way to clean this up?

Related to #5 https://github.com/open-city/chicago-river-sewage/issues/5

— Reply to this email directly or view it on GitHubhttps://github.com/open-city/chicago-river-sewage/issues/6 .

773.888.2718 2231 N. Monticello Ave Chicago, IL 60647

iandees commented 10 years ago

Trace more of the rivers you care about in OSM and then use a simplification algorithm to make the file smaller.

mapmeld commented 10 years ago

I took a look at this in QGIS. Simplifying to a 5mb file makes it too imprecise, TopoJSON brings it down to 3.7mb, but it's still a lot to render on the map.

I think the best option might be to spend time selecting and merging things in QGIS, or to go down the river making a list of IDs which you want associated with that branch. You need to have that anyway to make the color-coding work.

fgregg commented 10 years ago

Done: https://github.com/open-city/chicago-river-sewage/blob/cso-charting/data/processors/river-viewer/caws.geojson

fgregg commented 10 years ago

Almost! Misses the north branch where we do have CSO events.

derekeder commented 10 years ago

@sbelsow found a good source for riverways in IL: http://crystal.isgs.uiuc.edu/nsdihome/webdocs/st-hydro.html

File: http://crystal.isgs.uiuc.edu/nsdihome/browse/statewide/zips/IL_Streams_From_100K_DLG_Ln.zip

derekeder commented 10 years ago

closed with https://github.com/open-city/chicago-river-sewage/commit/13dcc37092cbbbd22c8cd509e7d3bf541da5050e