Geoprocessing - Desktop GIS: Mapping the Planet with Open Source Tools - page 162

Figure 10.9: Rivers clipped to a quadrangle boundary
Clipping features from larger map layers to create smaller ones is a
common GIS operation, especially when your project is focused in a
smaller area and you don't need all the extra features running around
your map. The GRASS v.overlay command provides a quick and easy
way to subset your data into new map layers.
We'll talk about some other vector overlay operations when we get to
Chapter 12 , Getting the Most Out of QGIS and GRASS Integration, on
page 208 .