In regions of high-altitude people move from valleys to the higher reaches of mountains along with their cattle during summer and come back to the valleys during the winter. These people have their permanent homes in the valleys, and they move to the higher areas to graze their cattle there. When the higher reaches of the mountains become too cold, they come back to the lower valleys. Their annual movement is always along some fixed routes and generally their grazing areas are also fixed. This type of altitudinal migration is called TRANS-HUMANCE.

Gaddi tribes of Himachal Pradesh and Bakarwals in Jammu & Kashmir practices this type of migration.

On the basis of source of origin and destination of migrant population, migration can be divided into four types.

(a) Rural to Rural

(b) Rural to Urban

(c) Urban to Urban

(d) Urban to Rural

Indian scenario (according to the 2011 census data)

The state of Maharashtra accommodates largest number of migrants followed by Delhi and West Bengal. On the other hand, Uttar Pradesh followed by Bihar and Rajasthan are the three top contributors of out migrants. On net migration scale i.e., the differences between in-migrants and out-migrants Maharashtra stands at the top of the list followed by Delhi. As per the 2011 census, there were 453.6 million Indians who were migrants.

 (a) Intra-State Migration – The majority of the migrants belong to this category. According to 2001 Census, 80.73 millions of people are intra-state migrants.

• Among these migrants, overwhelming population i.e., 60.5 percent were rural to rural migrants whereas only 12.3 percent belonged to the category of urban-to-urban migrants.
• The remaining 17.6 percent migrants belonged to the category of rural to urban and 6.5% belonged to the urban to rural areas.
• The rest 3.1 percent is unclassified which means that the respondents have not mentioned any stream.
• Among intra-state migrants about 70 percent were females. This high percentage was mainly due to marriages. About 69% of the female migrants were from rural-to-rural migration. 9.7 percent of female migrants moved from one urban centre to another, 13.6 percent moved from rural to urban areas and only 5.6 percent from urban to rural areas. The rest 2.6 percent is unclassified.
• In the case of male migrants, 41.6 percent belonged to the category of rural-to-rural migrants, 18.3 percent belonged to urban to urban, 27.1 percent belonged to rural to urban and 8.6 percent were urban to rural. The major chunk of population who moved from rural-to-rural areas are mainly moved out in search of employment.

(b) Inter-State Migration

In India inter-state migration is limited in comparison to intra-state migration. According to 2001 Census, 17 million people were inter-state migrants.

• Out of these 17 million people, 26.6 percent belonged to the category of rural-to-rural migrants, 26.7 belonged to the category of urban to urban, 37.9 belonged to rural to urban and 6.3 percent belonged to urban to rural. The rest 2.6% is unclassified.
• About half of all inter-state migrants were males. Among them 26.6% percent moved within the rural areas, 26.7 percent moved within the urban areas. 37.9 percent of migrants moved from rural to urban areas and 6.3 percent from urban to rural areas.