Ans: Trade and Industrial Areas:
The areas which are located on or near trade highways have an increase in
population. Besides land routes, sea and air routes hold great importance as
well. Therefore, those cities and areas which have large seaports and
airports along with trade markets grow in population as well. Those areas
where industries are located provide sources of income and so have more
population. Faisalabad has become the 3rd largest city of Pakistan due to
industrial development. Industries are also one of the reasons for the dense
population of Karachi, Lahore, Gujranwala, Sialkot, etc.