grdvolume - Calculating volume under a surface within a contour
grdvolume grdfile [ -Ccval or -Clow/high/delta ] [ -Lbase ] [
-Rwest/east/south/north[r] ] [ -S[k] ] [ -T ] [ -V[l] ] [
grdvolume reads a 2-D binary grd file and calculates the volume
contained between the surface and the plane specified by the given
contour (or zero if not given). Alternatively, specify a range of
contours to be tried and grdvolume will determine the volume and area
inside the contour for all contour values. The contour that produced
the maximum mean height (volume/area) is reported as well. This
feature may be used with grdfilter in designing an Optimal Robust
Separator [Wessel, 1998].
The name of the input 2-D binary grd file.
No space between the option flag and the associated arguments.
-C find area and volume inside the cval contour. Alternatively,
search using all contours from low to high in steps of delta.
[Default returns entire area and volume of grid].
-L Also add in the volume from the level of the contour down to base
[Default base is contour].
-S Convert degrees to meters, append k for km [Default is
-T Use curvature minimum rather than maximum height to find best
contour value (when contour search is selected with -C).
-R west, east, south, and north specify the Region of interest. To
specify boundaries in degrees and minutes [and seconds], use the
dd:mm[:ss] format. Append r if lower left and upper right map
coordinates are given instead of wesn.
-V Selects verbose mode, which will send progress reports to stderr
[Default runs "silently"]. Append l to see all the results for
each contour level tested (when contour search has been
-Z Optionally subtract shift before scaling data by fact. [Default
is no scaling]. (Numbers in -C, -L refer to values after this
scaling has occurred).
To determine the volume in km^3 under the surface hawaii_topo.grd
(height in km), try
grdvolume hawaii_topo.grd -Sk
To find the volume between the surface peaks.grd and the contour z =
grdvolume peaks.grd -Sk -C250
To search for the contour, between 100 and 300 in steps of 10, that
maximizes the ratio of volume to surface area for the file peaks.grd,
grdvolume peaks.grd -Sk -C100/300/10 > results.d
Wessel, P., 1998, An empirical method for optimal robust regional-
residual separation of geophysical data, Math. Geol., 30(4), 391-408.
Man(1) output converted with