Re-use of flowaccumualtion and flow direction map

tpilz / lumpR

Landscape Unit Mapping Program for R

GNU General Public License v3.0

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Re-use of flowaccumualtion and flow direction map #58

Open TillF opened 10 months ago

TillF commented 10 months ago

Currently, flowaccumulation and flow direction map are both being calculated in calc_subbas() and lump_grass_prep(). If would save lots of cimputational time, if r.watershed could re-use any exsisting maps. Currently, this doesn't seem to be possible though. Let's verify this, though.

tpilz commented 10 months ago

calc_subbas() takes them as optional input if they already exist. I'm rather sure I paid some attention that r.watershed is not executed more often than necessary.

TillF commented 10 months ago

r.watershed wird bis zu 3 mal aufgerufen: a) zur TEZG-Bestimmung nach Schwellenwert b) zur TEZG-Bestimmung auf Auslasspunkt c) zur Konstruktion der EHAs

Jedes mal wird flowaccum neu berechnet, weil r.watershed diese nicht bereits übernehmen kann. Wenn es eine Alternative zu r.watershed gäbe, die das könnte, würde das Einsparungen bringen.