Re: [HOT] Waterway - Determining Flow Direction

[Mike Thompson]

On Tue, Apr 5, 2016 at 3:13 PM, Paul Norman  wrote:

> On 4/5/2016 11:49 AM, Michael Heißmeier wrote:
>
> Hi Mike,
>
> there is another option which I occasionally use. Depending on the area in
> question you might find more-or-less outdated US military maps (JOG/AMS
> etc.) which have the advantage that there is no copyright associated with
> them. They tend to be fairly exact as far as terrain and waterbodies are
> concerned and sometimes are good sources for the names of such bodies as
> well.
>
> For your specific area the one to choose would be
>
> http://www.lib.utexas.edu/maps/jog/southern_africa/se-35-7-binga-southern_rhodesia-zambia.jpg
>
>
> The map you linked is copyrighted and published in 1972 by the Director of
> Military Survey, Ministry of Defense, United Kingdom, so we can't use it.
>
> Paul, thanks for pointing this out before I was able to start using it or
had worked it into the instructions for the mapathon.
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Re: [HOT] Waterway - Determining Flow Direction

[Paul Norman]

On 4/5/2016 11:49 AM, Michael Heißmeier wrote:

Hi Mike,

there is another option which I occasionally use. Depending on the 
area in question you might find more-or-less outdated US military maps 
(JOG/AMS etc.) which have the advantage that there is no copyright 
associated with them. They tend to be fairly exact as far as terrain 
and waterbodies are concerned and sometimes are good sources for the 
names of such bodies as well.


For your specific area the one to choose would be
http://www.lib.utexas.edu/maps/jog/southern_africa/se-35-7-binga-southern_rhodesia-zambia.jpg


The map you linked is copyrighted and published in 1972 by the Director 
of Military Survey, Ministry of Defense, United Kingdom, so we can't use it.
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Re: [HOT] Waterway - Determining Flow Direction

[Arun Ganesh]

Getting the flow directions correct can be tricky. In any case, its should
be easy to find and correct waterways with an incorrect flow using a tool
like osmose http://osmose.openstreetmap.fr/en/map/

Have fun at the mapathon!

On Wed, Apr 6, 2016 at 12:35 AM, Mike Thompson  wrote:

>
>
> On Tue, Apr 5, 2016 at 12:40 PM, Michael Heißmeier <
> michae...@digital-filestore.de> wrote:
>
>> Hi Mike,
>>
>> there is another option which I occasionally use. Depending on the area
>> in question you might find more-or-less outdated US military maps (JOG/AMS
>> etc.) which have the advantage that there is no copyright associated with
>> them. They tend to be fairly exact as far as terrain and waterbodies are
>> concerned and sometimes are good sources for the names of such bodies as
>> well.
>>
> Wow, this is an excellent source! Thanks.  Might it be a good idea of HOT
> projects mentioned this source where available and appropriate?
>
> Mike
>
>
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>


-- 
Arun Ganesh
@planemad

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Re: [HOT] Waterway - Determining Flow Direction

[Mike Thompson]

On Tue, Apr 5, 2016 at 12:53 PM, Ezra Boyd  wrote:

>
> -  Look for things like locks, spillways, bridges, etc. that would cause
> whitewater and use that to determine flow direction
> -  Rivers and streams tend to flow toward larger waterbodies, such as
> lakes, gulfs and oceans.  Look for things likes deltas to help determine
> flow direction
> -  Also, they tend to converge with other rivers & streams downstream.
> Look for the Y's where two rivers converge, with the being toward the base
> of the Y
> -  Rivers and streams tend to be wider downstream.
> -  Because of above, larger navigational vessels tend to be found
> downstream
> -  Because of the above, larger settlements tend to be found downstream.
>
Thanks Ezra.  All good advice.  I will caution that most lakes will have at
least one river/stream flowing away from them. The exception is a lake that
is part of an endorheic basin[1] such as the Great Salt Lake in the US.

[1] https://en.wikipedia.org/wiki/Endorheic_basin

>
>
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Re: [HOT] Waterway - Determining Flow Direction

[Mike Thompson]

On Tue, Apr 5, 2016 at 12:40 PM, Michael Heißmeier <
michae...@digital-filestore.de> wrote:

> Hi Mike,
>
> there is another option which I occasionally use. Depending on the area in
> question you might find more-or-less outdated US military maps (JOG/AMS
> etc.) which have the advantage that there is no copyright associated with
> them. They tend to be fairly exact as far as terrain and waterbodies are
> concerned and sometimes are good sources for the names of such bodies as
> well.
>
Wow, this is an excellent source! Thanks.  Might it be a good idea of HOT
projects mentioned this source where available and appropriate?

Mike
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Re: [HOT] Waterway - Determining Flow Direction

[Bryan Housel]

Ah, sorry I read your email too quickly.
I’ll add OpenCycleMap as a background layer in iD - I agree that the contour 
data is useful.
In the meantime, yes you can add it as a custom background layer as Blake 
described.
Thanks, Bryan



> On Apr 5, 2016, at 2:04 PM, Mike Thompson  wrote:
> 
> 
> 
> On Tue, Apr 5, 2016 at 11:57 AM, Bryan Housel  > wrote:
> Hi Mike, waterways in iD are rendered with directional arrows (see attached). 
> OpenStreetMap convention is to draw the way in the direction of the flow, 
> much like oneway roads.
> Thanks for your response.
> 
> I didn't explain the problem well enough. The issue isn't determining the 
> direction of the geometry once it is drawn, but determining the real life 
> flow direction based solely on overhead imagery (so one can draw the geometry 
> correctly). 
> 
> Mike
> 

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Re: [HOT] Waterway - Determining Flow Direction

[Ezra Boyd]

Here are a few other tips that might work:
-  Look for things like locks, spillways, bridges, etc. that would cause
whitewater and use that to determine flow direction
-  Rivers and streams tend to flow toward larger waterbodies, such as
lakes, gulfs and oceans.  Look for things likes deltas to help determine
flow direction
-  Also, they tend to converge with other rivers & streams downstream.
Look for the Y's where two rivers converge, with the being toward the base
of the Y
-  Rivers and streams tend to be wider downstream.
-  Because of above, larger navigational vessels tend to be found downstream
-  Because of the above, larger settlements tend to be found downstream.

Of course, these are general rules of thumb and there are exceptions.  For
example, a river might widen into a lake and then have a narrow stream
flowing from the lake.  Likewise, dredging may artificially widen a river
segment between two industrial centers.  Still, I think these rules along
with Blake's tips should get you most of the way there.

Hope it helps!!!

Ezra


On Tue, Apr 5, 2016 at 1:23 PM, Mike Thompson  wrote:

>
>
> On Tue, Apr 5, 2016 at 12:11 PM, Blake Girardot 
> wrote:
>
>>  seeing the area might help a bit to see if anyone has any tips.
>
> The general area is that which is around this node:
> https://www.openstreetmap.org/node/4100183177 (note I have already mapped
> the waterway which that node is part of using JOSM and OCM)
>
>
>>
>> whitewater points in the direction of flow, meaning it trails after the
>> obstruction in the waterway.
>>
> Good tip!  I hadn't thought of that..  In this case these appear to be
> intermittent waterways (albeit rather wide), and there is very little water
> shown in the Bing imagery, let alone whitewater.
>
>>
>> you can also put the opencyclemap url into the custom background in iD,
>> the url is:
>> http://tile.opencyclemap.org/cycle/{zoom}/{x}/{y}.png
>
> I was trying to keep this simple, but this might be the way to go.
>
>>
>>
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>


-- 
Ezra Boyd, PhD
DisasterMap.net, LLC 
ezgis 7...@gmail.com 
(504)533-4447
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Re: [HOT] Waterway - Determining Flow Direction

[Michael Heißmeier]

Hi Mike,

there is another option which I occasionally use. Depending on the area in 
question you might find more-or-less outdated US military maps (JOG/AMS etc.) 
which have the advantage that there is no copyright associated with them. They 
tend to be fairly exact as far as terrain and waterbodies are concerned and 
sometimes are good sources for the names of such bodies as well.


For your specific area the one to choose would be
http://www.lib.utexas.edu/maps/jog/southern_africa/se-35-7-binga-southern_rhodesia-zambia.jpg

I attached a clip of it to this mail. Looks as if these intermittent rivers are 
visible on this map, flowing WSW into the lake.


Best Regards
/Michael
(osm:michael63) /
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Re: [HOT] Waterway - Determining Flow Direction

[Mike Thompson]

On Tue, Apr 5, 2016 at 12:11 PM, Blake Girardot  wrote:

>  seeing the area might help a bit to see if anyone has any tips.

The general area is that which is around this node:
https://www.openstreetmap.org/node/4100183177 (note I have already mapped
the waterway which that node is part of using JOSM and OCM)


>
> whitewater points in the direction of flow, meaning it trails after the
> obstruction in the waterway.
>
Good tip!  I hadn't thought of that..  In this case these appear to be
intermittent waterways (albeit rather wide), and there is very little water
shown in the Bing imagery, let alone whitewater.

>
> you can also put the opencyclemap url into the custom background in iD,
> the url is:
> http://tile.opencyclemap.org/cycle/{zoom}/{x}/{y}.png

I was trying to keep this simple, but this might be the way to go.

>
>
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Re: [HOT] Waterway - Determining Flow Direction

[Blake Girardot]

Hi Mike, seeing the area might help a bit to see if anyone has any tips. 
It can be difficult to get the water flow directions right even with OCM.


My general tips are, with limited effectiveness:

zoom out a lot to see what the general watershed and terrain looks like

whitewater points in the direction of flow, meaning it trails after the 
obstruction in the waterway.


Try and follow the waterway to where it connects up to larger or 
originates from.


you can also put the opencyclemap url into the custom background in iD, 
the url is:

http://tile.opencyclemap.org/cycle/{zoom}/{x}/{y}.png

Then just switch to it and switch back for mapping.

Cheers
blake





On 4/5/2016 7:33 PM, Mike Thompson wrote:

When editing in JOSM I use the OpenCycleMap layer to help determine the
direction a waterway flows (OpenCycleMap has elevation contour lines).
However, I will be hosting a mapathon where the participants will be
using iD. How might one determine flow direction in iD?

Mike


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Re: [HOT] Waterway - Determining Flow Direction

[Mike Thompson]

On Tue, Apr 5, 2016 at 11:42 AM, john whelan  wrote:

> Quietly do the rivers before anyone starts in JOSM?
>
> iD has its limitations so I'd be tempted to either accept that waterways
> will flow the wrong way 50% of the time and hope the validators will
> correct it or don't bother to map the waterways in iD.
>
Thanks John.  Those may be the only options, even if they are far less than
ideal.

Mike
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Re: [HOT] Waterway - Determining Flow Direction

[Bryan Housel]

Hi Mike, waterways in iD are rendered with directional arrows  (see screenshot: 
 http://i.imgur.com/E5n9SPM.png  ). 
OpenStreetMap convention is to draw the way in the direction of the flow, much 
like oneway roads.

Have a great mapathon!
Bryan



> On Apr 5, 2016, at 1:33 PM, Mike Thompson  wrote:
> 
> When editing in JOSM I use the OpenCycleMap layer to help determine the 
> direction a waterway flows (OpenCycleMap has elevation contour lines). 
> However, I will be hosting a mapathon where the participants will be using 
> iD. How might one determine flow direction in iD?
> 
> Mike
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