[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 <miketho16 at gmail.com> wrote:

>
>
> On Tue, Apr 5, 2016 at 12:11 PM, Blake Girardot <bgirardot at gmail.com>
> 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 <http://DisasterMap.net>
ezgis <ezgis76 at gmail.com>76 at gmail.com <ezgis76 at gmail.com>
(504)533-4447
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