GRASS GIS manual: r.clim

NAME

r.clim - Creates two raster map layers: 1. solar radiation 2. percentage relative humidity

KEYWORDS

SYNOPSIS

r.clim
r.clim help
r.clim [-v] tmin=name tmax=name prcp=name [elev=name] [slope=name] [aspect=name] lat=name [ehoriz=name] [whoriz=name] month=integer rad=name hum=name [--overwrite] [--verbose] [--quiet]

Flags:

-v: Run verbosely
--overwrite: Allow output files to overwrite existing files
--verbose: Verbose module output
--quiet: Quiet module output

Parameters:

tmin=name: Name of input raster map containing MINIMUM TEMPERATURE
tmax=name: Name of input raster map containing MAXIMUM TEMPERATURE
prcp=name: Name of input raster map containing PRECIPITATION in mm
elev=name: Name of input raster map containing ELEVATION (m)
slope=name: Name of input raster map containing SLOPE (degree)
aspect=name: Name of input raster map containing ASPECT (degree, anti-clockwise from E)
lat=name: Name of input raster map containing LATITUDE in decimal degrees
ehoriz=name: Name of input raster map containing EAST HORIZON (degree)
whoriz=name: Name of input raster map containing WEST HORIZON (degree)
month=integer: Number of the month in the year i.e. January=1, February=2,...
rad=name: Name of output raster map containing SOLAR RADIATION in W/m^2
hum=name: Name of output raster map containing RELATIVE HUMIDITY in %

DESCRIPTION

r.clim calculates solar radiation and percentage relative humidity maps. The calculation of the two values for each raster cell is based on the C code cclimm.c a simplified version of mtclim43.c by Peter Thornton (2000) of the NTSG, School of Forestry University of Montana. The cclimm.c code is thought for monthly data and doesn't consider arid correction so this module isn't indic ated for arid region.

The input units are:

Temperatures: degrees C
Precipitation: mm / day
Elevation: m
Slope: degrees
Aspect: degrees
Latitude: decimal degrees
E/W horizons: decimal degrees

while the output units are:

Relative humidity: %
Radiation: W/m2, average over daylight period

REFERENCE

C. Sboarina, 2002: Development of a complete climate database using a new GRASS module. In B. Benciolini, M. Ciolli, and P. Zatelli, editors, Proc. of the Open Source Free Software GIS - GRASS users conference 2002, Trento, Italy, 11-13 September 2002

AUTHOR

Chiara Sboarina, Centro di Ecologia Alpina - Viote del Monte Bondone (TN) - Italy (2001)
based on "mtclim43" by Peter Thornton (2000) of the NTSG, School of Forestry University of Montana.

Last changed: $Date$

Main index - raster index - Full index