出典:国際連合
When an individual migrates several times during a certain period, his or her moves may be distinguished according to the order of migration 1. The duration of residence 2 or duration of stay 2 refers either to the interval between the arrival in a place and the subsequent departure for another destination or to the interval since the most recent move. Return migration 3 involves movement back either to the initial area, or to any previous place of residence. Repeat migration 4 or chronic migration 4 refers to a tendency to migrate several times over a relatively short time interval. Rural-urban migration 5 sometimes takes the form of serial migration 6, stage migration 6 or step migration 6, as migrants tend to move to large cities as a final place of destination by a series of shorter, intermediate migrations to cities or areas of successively larger size.