बसाइँसराइका मापक र सहरीकरण

$\text{Immigration rate} = \frac{\text{Number of immigrants in a year}}{\text{Total population}} \times 1000 = \frac{40}{20000} \times 1000 = 2$

The immigration rate of the city was 2 per 1000 population.

Measures of Internal Migration

Internal migration is the movement of people within the boundaries of a country — from one district, province, or region to another. It is measured using the following main measures:

1. In-Migration Rate

It measures the volume of in-migration (people entering an area) per 1,000 population of the receiving (destination) area in a given year.

$In\text{-}Migration\ Rate = \frac{\text{Number of in-migrants in an area during a year}}{\text{Mid-year population of the same area}} \times 1000$

2. Out-Migration Rate

It measures the volume of out-migration (people leaving an area) per 1,000 population of the sending (origin) area in a given year.

$Out\text{-}Migration\ Rate = \frac{\text{Number of out-migrants from an area during a year}}{\text{Mid-year population of the same area}} \times 1000$

3. Net Migration Rate

It is the difference between in-migration and out-migration per 1,000 population of an area. It shows whether an area is gaining or losing population through migration.

$Net\ Migration\ Rate = \frac{\text{In-migrants} - \text{Out-migrants}}{\text{Mid-year population}} \times 1000$

• A positive value means net in-migration (population gain).
• A negative value means net out-migration (population loss).

4. Gross Migration Rate

It measures the total volume of migration (both in and out) per 1,000 population of an area.

$Gross\ Migration\ Rate = \frac{\text{In-migrants} + \text{Out-migrants}}{\text{Mid-year population}} \times 1000$

5. Net Migration (Absolute)

It is the actual number of persons gained or lost by an area through migration.

$Net\ Migration = \text{Total in-migrants} - \text{Total out-migrants}$

6. Migration Effectiveness Ratio (Efficiency of Migration)

It shows how effectively migration redistributes population, i.e., the proportion of total migration that results in net gain or loss.

$Migration\ Effectiveness\ Ratio = \frac{\text{Net migration}}{\text{Gross migration}} \times 1000$

7. Place-of-Birth Method (Lifetime Migration)

Persons whose place of birth differs from their place of residence (enumeration) are counted as lifetime migrants. The migration rate is:

$Lifetime\ Migration\ Rate = \frac{\text{Persons born elsewhere but residing in the area}}{\text{Total population of the area}} \times 1000$

8. Place-of-Last-Residence Method

Persons whose last previous residence differs from the present residence are counted as migrants. This captures recent or short-term migration better than the place-of-birth method.

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Note: In all the above rates, the mid-year population of the relevant area is used as the denominator, and the result is expressed per 1,000 population. In Nepal, internal migration is largely rural-to-urban and from the hills to the Tarai and major cities, driven mainly by employment, education, and marriage.