[GRASS-user] r.flow: define contributing area

[Rich Shepard]

On Tue, 4 Oct 2016, Johannes Radinger wrote:

> Maybe have a look at
> r.lake: https://grass.osgeo.org/grass70/manuals/r.lake.html. This module
> fills the area upstream a dam or a blocked stream.

Johannes/Thomas,

   I considered r.lake and r.damflood. What I will try to learn from the
manual pages (and references thereon) is whether either of those modules
require the blockage to be on a defined stream/river channel. Some lands can
be on flat land without a stream running through it. These could be a
suburban residential area, industrial/commercial area, or agricultural.
Normally, when precipitation saturates the soils the excess runs off the
surface and has a flow path to prevent flooding. When a drain, culvert, or
swale is blocked the surface water accumulates where it's not wanted.

   This time of year this happens right outside my house where the storm
drain grate in the street just off the curb between me and my neighbor is
covered with dead leaves and the water backs up. Sweeping away the leaves
clears this. But, this is the type of situation for which I need a solution:
where will water back up and flood if drainage from flat land is blocked.

   So, I'll read what I can find about r.lake and r.damflood and see if they
are suitable for this situation.

Thanks both of you,

Rich