Which one of the following is known as acceleration stage in the urbanization curve ?

The answer is B) Second stage. This question is based on Northam's S-curve, which describes how the urban share of population typically rises over time.

• First stage (initial stage): Urban share is low, roughly below 20 per cent, and growth is slow. This is not the acceleration phase.
• Second stage (acceleration stage): Urban share rises from about 20 to 50 per cent. Migration, industrialisation and natural increase push growth to its fastest rate here. This is the correct answer.
• Third stage (terminal stage): Urban share exceeds about 70 per cent. Growth slows as the urban population approaches saturation.
• Fourth stage: In extended versions of the model, this refers to later suburbanisation or counter-urbanisation. It is not the acceleration stage.

For Mains, India is still in the acceleration phase. The 2011 Census put urban share at about 31 per cent, so rapid urban growth calls for planning on housing, sanitation, transport and municipal finance. That is the logic behind the Smart Cities and AMRUT missions.

Trap: Candidates often assume the first rising phase of any curve is the acceleration stage. The question asks for the phase of fastest growth, which is the middle one.