The urban population in India in 1901 was only 25.9 million, constituting 10.9 per cent of the total population in 1901, which increased to 377.1 million accounts for 31.1 per cent of the total population in 2011 (Table-2). The urban population did not grow much until 1921 and the level of urbanization even showed a decline in 1911 owing to devastating plague epidemic of 1911, which spread mainly in the urban areas and brought exodus of urban population to rural areas. From the year 1921 onwards, the level of urbanisation grew steadily and very fast during the decade 1941-51 when the decennial urban growth rate was recorded as high as 41.4 percent due to the partition of the country in 1947 (Census of India 1991).The decline in the growth rate during 1951-61 was an artifact of the change in definition of urban resorted in 1961 census. As a result, about 800 towns have been declassified in 1961 census (Mohan and Pant, 1982).

In 1951-61 decade, a slowing of growth rate was noticed with the exponential growth of 2.3 with absolute growth of 16.4 million. This is mainly due to reorganization of states in 1956 and adoption of new distinctive classification rural-urban population (Ashish Bose, 1978). However, it can be noticed from table-4.2 that the highest in urban growth was observed during 1971-81 when the decennial growth rate raised to 46.1 per cent- the highest ever during the last century. Thereafter, the urban growth rate has slowed down, which declined to 31.4 percent in 2011(Table 2). It can be attributed to the mainly low volume of migration of people to urban areas apart from a steep decline in natural growth rate. Table-4.2 holds data on the growth of urban population in India during 1901-2011.

2 reveals that during eleven decades (1901 to 2011), the urban population increased by 15 times. Compared to the change in urban population, the number of towns only got 6.2 times during the same period (1,827 in 1901 to 5,161 of 2011). The net addition in urban population was 5.4 million during 1921-1931, which rose to 18.3 million during 1941-51 and to a sharp increase of 54.4 million during 1971-1981. The census of 2001 showed that the net addition of population was 67.8 million during 1991-2001 and 91.8 million during 2001-2011. Further, in the decade 2001-2011, a decline annual exponential rate in 2.7 was noticed, which was affected by the consistent fall in fertility level (Census of India, 1991).

Urbanization may be linked with details related to topography, transportation, land use, social structure and economic type, but is generally related to demography and economy in a city (Li, et al., 2002). The most important index in the study of urbanisation is distribution of population by different size classes, overtime, which reveals the population concentration across the cities/ towns by size class. In table-3, urbanization is analyzed by spatial urban form and its changes over time a period of eleven decades (1901-2011).It gives information on the size classes which are losing as well as gaining over a period of time. Urban units in India are classified into six classes. They are as follows: Class-I with a population of 1,00,000 and above; Class-II consists 99,999- 50,000; Class-III has 49,999-20,000; Class-IV holds 10,000-19,999; Class-V with a population of 5,000-9,999 and Class-VI contains less than 5,000. Proportion of Indian urban population concentration by Size Class of Cities/Towns for eleven decades (1901-2011) is given in Table 3.

3 depicts that the number of cities-towns in class-I to class-IV has been increasing during 1901-2011, while the class class-V and class-VI towns where fluctuating during 1901-1951, thereafter rapidly declining. Thus, the Indian urbanization scenario shows a high concentration of population in large cities/towns signals the enormity of the urban problems such as socio-economic, environmental and administrative etc.

The cities with a million and more population deserve a special category in India’s urbanisation because of their large size and economic dominance in the countries. Such cities are called as million plus or metropolitan cities. Million plus cities are a major source of economic activities, employment generation and prosperity in an economy. With rising income levels, people demand more goods and services, which become an important factor for them to live in cities. The cities attract more skilled labour, which, in turn, facilitates investments to open new firms and foster industrial development in the cities. Cities are the reflection of global integration of an economy as a majority of foreign firms operate their businesses in big cities and attract experts to live and work there. Over the last five decades, the world has faced dramatic growth of its urban population. The number of so-called mega cities increased in the period from 1975 until today from 4 to 22, mostly in less developed regions (Munchner Ruck, 2005). Particularly, Indian mega cities are among the most dynamic regions on the earth. During the last five decades, the population of India (As per 2011 census, 1.2 billion) has grown two and a half times, but the urban population has grown nearly five times. Here, an attempt is made to trace the trend and pattern of urbanisation in million plus cities in India over period of eleven decades.

Table 4 depicts that the number of million plus cities in India doubles during 1901-1941, rose to 12 cities in 1981 and grew to 53 by 2011; thereby India has the largest concentration of mega cities in the world, while, the inhabitants of million plus cities had rapidly increased in recent decades than earlier periods. In 1901 census, only one city had recorded 1.5 million population, increased to two cities constituting a population of 5.3 million in 1941, and further rose to five cities with population of 11.8 million in 1951, can be found from table-4. From, 1961 onwards, the million plus cities and concentration of population in these had been rapidly increased to seven cities holding population of 27.8 million, increased to twenty-three towns with inhabitants of 70.7 million in 1991 and rose to fifty-three cities comprising a population of 160.7 million by the year 2011. Thus, a huge share of urban population of India has been concentrating in million plus cities, which is clearly visible by noticing Population per million plus cities. It was 1.5 million in 1901, increased to 2.7 million in 1941 and grew to 3.1 million in 2001 census and recorded as 3.0 percent in 2011.

Also, the volume of urbanisation in million plus cities can be noticed through their share in a Population of Million Cities as percent of India's population, percentage of total urban population and Cumulative Growth Index of Population in million plus cities. Of the 53 cities that have upgraded to million plus status, 48 cities were in existence in 1901 also. These cities contained 12 percent of the total urban population of the country. This period contains frequent epidemic diseases that not only took a toll of millions of human lives, but also disrupted the economic life of urban and rural areas alike. Moreover, the decline of India’s exports of cotton, leather, sugar and coffee in the face of growing international competition was also responsible for arresting the growth of many markets, manufacturing and port towns.

Table 5 shows that in Kerala, three million plus cities like Kannur, Kollam, Malapuram and Thrissur have shown an abnormal increase in the populationrecording growth rate more than 100 percent during 2001-2011. This may not be due to natural increase, but due to the three type process of change in the territorial boundaries of these urban agglomerations through incorporation of the surrounding rural areas and merging of the towns into them apart from inflow of people. Growth of population during 1991-2011 in million plus cities at the time of the census 1991 and have attained the status in 2011 indicate the different growth rate. The fastest growth documented on those urban centres which are become million plus cities in 2001-2011 census in comparison to the existed million plus cities. The natural growth of urban population, in-migration from rural area as well as smaller urban places and expansion of urban boundaries which include adjacent towns and villages contributed the rapid growth. Evidence indicates that, about two- thirds of an increase in the urban population of the large cities as a result of natural increase (Singh, 1992) and remaining as the consequences of in-migration (Oberai, 1993). Reasonably, Southern India is more urbanized than its northern counterpart. The coastal areas are characterised by development of port areas, industrialisation and commercialization resulted in a higher degree of urbanisation.

Although the present share of the urban population in India is relatively small, namely about 31.2 percent, but it is quite large in absolute number, namely, about 377 million. Moreover, the large mega-cities in the country are showing an imbalance fast growth pace over the past decades.

Million plus cities has become congested, clogged, polluted, and also show significant social polarization. Thus, the top-heavy character of India’s urban system also adversely impacts the balanced regional development of the country. The government policies aimed at tackling the urban challenges by developing small as well as medium towns to divert migration to larger cities and develop rural areas to curtail out-migration.

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