rsaga.wetness.index {RSAGA} | R Documentation |
Calculate the SAGA Wetness Index (SWI), a modified topographic wetness index (TWI)
rsaga.wetness.index( in.dem, out.wetness.index, out.carea, out.cslope, out.mod.carea, t.param, ...)
in.dem |
input: digital elevation model (DEM) as SAGA grid file
(default file extension: .sgrd ) |
out.wetness.index |
output (optional): wetness index grid. Existing files of the same name will be overwritten! |
out.carea |
output (optional): catchment area |
out.cslope |
output (optional): catchment slope |
out.mod.carea |
output (optional): modified catchment area |
t.param |
positive numeric value (optional): undocumented |
... |
optional arguments to be passed to rsaga.geoprocessor ,
including the env RSAGA geoprocessing environment |
The SAGA Wetness Index is similar to the
Topographic Wetness Index (TWI), but it is based on a modified
catchment area calculation (out.mod.carea
), which does
not treat the flow as a thin film as done in the calculation of
catchment areas in conventional algorithms. As a result, the
SWI tends to assign a more realistic, higher potential soil wetness
than the TWI to grid cells situated in valley floors with a small
vertical distance to a channel.
The type of object returned depends on the intern
argument
passed to the rsaga.geoprocessor
. For intern=FALSE
it is a numerical error code (0: success), or otherwise (default)
a character vector with the module's console output.
This function uses module 15 from the SAGA library
ta_hydrology
.
Alexander Brenning (R interface), Juergen Boehner and Olaf Conrad (SAGA module)
Boehner, J., Koethe, R. Conrad, O., Gross, J., Ringeler, A., Selige, T. (2002): Soil Regionalisation by Means of Terrain Analysis and Process Parameterisation. In: Micheli, E., Nachtergaele, F., Montanarella, L. (ed.): Soil Classification 2001. European Soil Bureau, Research Report No. 7, EUR 20398 EN, Luxembourg. pp.213-222.
rsaga.parallel.processing
,
rsaga.geoprocessor
, rsaga.env
## Not run: # using SAGA grids: rsaga.wetness.index("dem.sgrd","swi.sgrd") ## End(Not run)