Geography

People move to cities for Social , Economic and Environmental factors. 

Environmental 

There are poor living conditions and the ground is not very fertile due to drought. This causes crop failure which can then lead to starvation and a loss of income for farmers and the locals. However, if people move to the cities then these problems become less significant due to the fertile soil and more amount of farm land. 

Economic

The main economic factor is the lack of jobs and work provided. This of course is essential and well paid jobs are very uncommon in the sparse populated areas of the world. As a result of this , there are less emergency services and little potential to earn money. Moving to the city can solve this as there are more job opportunities including well paid jobs meaning that there will be more services and less poverty. 

Social 

Poor education and health care is one of the biggest social push factor as it means that death and infant mortality rates will be increasingly high and less children will be in education meaning that they will be more likely to go into gangs and do work in the drug dealing business. A pull factor in the cities is that religious activities are made safer, more schools are built and there are more heathcare services such as the NHS that ensure that the wellbeing of everyone is the best possible.