On Jan 15, 2009, at 5:22 AM, <grass-dev-request@lists.osgeo.org> wrote:
Date: Thu, 15 Jan 2009 09:39:00 -0000
From: "GRASS GIS" <trac@osgeo.org>
Subject: [GRASS-dev] Re: [GRASS GIS] #398: r.watershed with MFD
To: undisclosed-recipients:;
Message-ID: <048.b6a7364e017fd287d20f06fe708aedbe@osgeo.org>
Content-Type: text/plain; charset="utf-8"#398: r.watershed with MFD
--------------------------+-------------------------------------------------
Reporter: mmetz | Owner: grass-dev@lists.osgeo.org
Type: enhancement | Status: reopened
Priority: minor | Milestone: 7.0.0
Component: Raster | Version: svn-trunk
Resolution: | Keywords:
Platform: Unspecified | Cpu: Unspecified
--------------------------+-------------------------------------------------
Comment (by mmetz):I have submitted a new version of r.watershed to trunk with various
changesMFD is fully supported: drainage directions, stream segments, basins,
half-basins, RUSLE LS and S factors are all in accordance with MFD flow
accumulation.The module is slightly faster and uses a bit less memory. See updated
documentation to estimate memory requirements for the ram (all in memory)
mode (max 31 MB of RAM for 1 million cells).It is no longer necessary to create a MASK for cells with unknown
elevation (NULL values). All cells with unknown elevation (masked or NULL
values) are skipped. Zero and negative values are valid elevation values.The color rules generated by the module for flow accumulation have worked
for all tests so far and allow visual inspection without manually
assigning a color table. I'm using standard deviation and log transform,
based on Hamish's (I think) suggestions. Visual output is obsolete but
left for comparison.The output drainage direction is slightly changed in case an input map
with real depressions was supplied. Previously, real depressions had a
drainage direction of -1, but -1 was and is a valid drainage direction
indicating a drainage of 45 degree CCW from East towards a cell with
unknown elevation. Therefore real depressions have now a drainage
direction of 0. As before, if a cell drains due East the drainage
direction is 360 degrees, 0 (zero) as drainage direction was unused.RUSLE LS and S factor output maps are now of type DCELL without
multiplication by 100. Both factors have always been processed as type
double, previously the output maps for the two factors were written out by
typecasting from (DCELL * 100) to CELL.Please read the updated documentation before using the new module.
Best regards,
Markus,
Can this go into develbranch_6 too?
Michael