[HOT] What's water?

Prabhas Pokharel prabhas.pokharel at gmail.com
Mon May 4 03:59:20 UTC 2015

On Mon, May 4, 2015 at 9:33 AM, Pat Tressel <ptressel at myuw.net> wrote:

> ;-)
> I'm seeing some rivers mapped in areas that didn't have high-res imagery,
> that (in the DG imagery) cross over dry land, or through areas were tree
> tops are visible against a dark background that could be either water or
> shadow -- it's a dark gray-purple.  What I'm interpreting as the actual
> river channel is more turquoise and has (what look like) white rapids.  The
> imagery has no clouds, and land looks fairly dry, so this imagery may,
> perhaps, be dry season.
> Note the previously mapped rivers in this area are very rough -- points
> are far apart -- which implies they were mapped from low-res imagery.
> Some questions:
> Is there a large change in water volume in rivers during the dry season?
> I'm wondering if water recedes to the deepest channel, and does show more
> whitewater then.

Yes, changes in water volumes between wet and dry season can be immense in
Nepal. Some stream beds may also go dry in the dry season.
I would guess that some mountain streams may behave as you suggested, but
generally, my expectation would be for more whitewater in the wet season.

> Do trees grow in standing water (deep enough to appear dark) in Nepal?
> That's not unheard of -- it's true in the Everglades in Florida.  Or is an
> area with treetops and dark between more likely dry but shadowed?

Generally, most of the water in Nepal flows fast (we have lots of elevation
changes), and there are very rarely trees growing in standing/moving water
as in Florida.
I don't understand your second question.

> Thanks!
> -- Pat
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Prabhas Pokharel
twitter/skype/facebook/whatever: prabhasp
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