phicontour {viadam} | R Documentation |
Computes the “deflecting angle” of contour lines on a dam side from deflecting angle, slope of the terrain, and the angle of the dam side with respect to the terrain.
phicontour(phi,psi,alfa)
phi |
deflecting angle with respect to the direction of steepest decent in a sloping coordinate system aligned with the terrain. |
psi |
the slope of the terrain. |
alfa |
the angle of the dam side with respect to the sloping terrain in the direction normal to the dam axis in a plane normal to the upstream terrain. |
phicontour
returns a vector of angles
with the same number of elements as phi
, psi
or alfa
.
The returned “deflecting angle” of the contour lines on the dam side is defined in the map plane.
This function is useful in an analysis of the flow of avalanches against natural obstructions where a “dam axis” is in many cases not easily defined. The returned “deflecting angle” of the contour lines may be compared with angles measured from maps and used to compute the deflecting angles phi
and phih
(see phi2phi
) corresponding to a dam that is dynamically equivalent to the terrain obstruction.
The angles phi
, psi
and alfa
are given in radians.
Tomas Johannesson
vdamheight
, sdamslope
, damangle
and phi2phi
.
## Not run: phicontour(25*pi/180,10*pi/180,40*pi/180) ## End(Not run)