Geoprocessing - Desktop GIS: Mapping the Planet with Open Source Tools - page 161

Figure 10.8: Rivers and the quadrangle for clipping
This gives us the new vector map tana5 that contains just the quadran-
gle of interest. This is the same method we used in our raster clipping
process. To clip out the rivers, we simply do an intersection of the two
maps using the v.overlay command:
v.overlay ainput=majrivers atype=line binput=tana5 operator=and \
output=majrivers_tana5
In Figure 10.9 , on the next page, you can see the result of the clipping
operation. The rivers that fall within the Tanana A5 quadrangle are all
that remain in our new vector layer ( majrivers_tana5 ). We've also included
the Tanana A5 quadrangle as a backdrop in the figure. Looking at the
v.overlay command, you can see that we specified the majrivers map as
the first input and indicated its type using the atype parameter. The
tana5 vector map we created using v.extract was specified as the sec-
ond input map using the binput parameter. The key in this operation is
declaring the proper operator ( and ) since v.overlay has four possibilities.