QGIS Python Plugins Repository
Plugin: Join multiple lines
Permanently join multiple lines
After selecting multiple features of a line layer, this plugin can merge them into one feature with a continuous line.
The plugin will automatically put the selected lines in a geographically logical order and direction. If the end points of two lines do not match exactly, a line segment between both points is added to make the end result a single, continuous line. The attributes of the new line will be those of one of the selected features, but one cannot predict which one.