Luca Delucchi 021fa9d879 r.topidx: added examples and figures, thanks to Jerry Huang and Google Code-in 7 年之前
..
Makefile d6700ffb2c Update LIBES, DEPENDENCIES from linkage database 15 年之前
README db49180dd7 welcome to GRASS 7.0.svn 17 年之前
arc.to.gridatb.pl 7da91113a6 rename perl scripts to make it more obvious what they are (merge from devbr6) 13 年之前
file_io.c 7a89c7d27d parameter descriptions updated; routine names changed 11 年之前
global.h ba3050fee3 Easy-to-read macro names 11 年之前
gridatb.to.arc.pl 7da91113a6 rename perl scripts to make it more obvious what they are (merge from devbr6) 13 年之前
main.c 3fc9d69249 r.watershed, r.topidx: more keywords 7 年之前
r.topidx.html 021fa9d879 r.topidx: added examples and figures, thanks to Jerry Huang and Google Code-in 7 年之前
r_topidx.png 021fa9d879 r.topidx: added examples and figures, thanks to Jerry Huang and Google Code-in 7 年之前
topidx.c 822f70d04b r.topidx: indent 10 年之前

README

Main algorithm sources are rewritten from GRIDATB.FOR.
GRIDATB.FOR is available from http://www.es.lancs.ac.uk/hfdg/topmodel.html.

Thanks to Keith Beven.



[r.topidx]
creates topographic index, ln(a/tan(beta)), map from elevation map.

where
a: the area of the hillslope per unit contour length that drains
through any point

tan(beta): the local surface topographic slope
(delta vertical) / (delta horizontal)


Elevation map need not to be rectangular if study basin was already determined.
Non-interesting region may have NULL values. Study basin map can be taken
from r.water.outlet then the following r.mapcalc statements will create
study basin extracted elevation map.

r.mapcalc "belev = if(isnull(basin), basin, elev)"