Powerpoint presentation on population dynamics.pptx

Powerpoint presentation on population dynamics.pptx

1. Population dynamics Population dynamics is the branch of life sciences that studies short-term and long-term changes in the size and composition of populations, and the biological and environmental processes influencing those changes.

2. Factors involved in population dynamics

3. Population studies Population studies are concerned not only with population variables but also with relationships between population changes & other variables – social, economic, political, biological, genetic, geographical, environmental, health.

4. Definition of Key Words Size refers to the number persons in the population Distribution refers to the arrangement of the population in space at a given time Structure is the distribution of population among its sex & age groupings

5. Change is the growth or decline of the total population or one of its structural units. The components of change total population are births, deaths, & migrations Age-Sex Composition of a population refers to the proportion of males & females in different age-groups .

6. Net-Migration refers to the total number of persons added or subtracted from a population as a result of the combined effect of immigration & emigration immigration & emigration

7. Urbanization refers to mass migration of rural population into urban centers resulting in increasing the urban population & growth of cities Population Growth Rate (%/ year) is the rate at which a given population is expected to increase in a given period of time. Population Doubling Time refers to the time that would take for a population to double.

8. Replacement Level Fertility (or Zero population growth) is activated when a couple has two births during their reproductive life, just enough to replace themselves .

9. Population dynamics There are four ways in which the number of people in an area can change during two time periods t0 & t1 Pt1 = Pto + (B – D) + (IM – OM) Thus the population of an area may change due to natural reasons (B – D) known as natural increase or due to migration (IM – OM) known as net-migration . Subsequently: Population Growth = Natural Increase + Net Migration

10. Population composition Composition is a property of a group of people. It describes how the total given population is constituted (e.g. 51% males, 20% below age 5, 85% healthy 7& 30% employed etc).

11. Dependency Ratio = Children + Elderly X 100 Working Age = Pop below 15 + 65 & above X 100 Pop 15 – 64 years Sex Ratio : The overall sex ratio is simply the ratio of males to females in the population Sex Ratio = Number of Males X 100 Number of Females

12. IMPACT OF POPULATION GROWTH: Agriculture Economy and urbanization Food and nutrition Literacy and education Labor force and employment Clothing and housing Health care services Water supply and environment

13. APPROACHES TO POPULATION CONTROL Social policies and social changes Involuntary approaches to population control Family planning approach to fertility control

14. Demography derived from two words Demography is scientific study of human population Demos + graphy

15. Three phenomena in Demography Changes in population size Composition of population Population distribution in space

16. Social mobility Migration Marriage Mortality Fertility 5 demographic processes:

17. Demographic cycle EARLY EXPANDING LATE EXPANDING LOW STATIONERY DECLINING HIGH STATIONERY

18. Demographic trends: India 2.4% world land area & 17% of world’s population 2000- 11 th May, 1 billion

19. Age and sex composition Age pyramid Sex ratio Dependency Ratio Density of population Family size Urbanization Literacy & Education Life Expectancy

20. Age & sex composition 0-14 yrs male population 1% more than female, 60+ female population 0.6% more than male Proportion < 15 yrs decline, elderly > burden on health services.

21. Age pyramid broad base tapering top

22. Sex Ratio No of females/1000 males -mortality -sex selective migration -sex ratio at birth 2004 -06 892 0-4 yrs 908 Kerala only state with 1,058 females per 1000 males

23. Dependency Ratio Total dependency ratio= 0-14 years +65 years and above 15 to 65 years Societal dependency ratio Density of the population Number of persons living per square kilometer

24. Family size The total number of children a woman has borne at a point in time. Depends on: Duration of marriage, education of couple, the number of live births and living children, preference of male child, desired family size etc. Two child family norm

25. Urbanization Increase attributed to: Natural growth, migration from villages, Attraction of better living conditions availability of social services. Mega-cities- those with population of 10 million or more Mumbai, Kolkata, Delhi Literacy and education Life Expectancy

26. Vital statistics Statistics concerning the important events in human life, such as births, deaths, marriages, and migration

27. components Demography & vital events Health status-mortality , morbidity ,disability & quality of life Health resources-facilities , beds , manpower Financial statistics

28. Sources of vital statistics Registration Method : This method consists of continuous and permanent -recording of births, deaths, marriages, migration, etc Census The census provide the vital statistics information such as age, sex, marital status, education level, occupation, religion, etc. However, these information pertain to the census years only (once in ten years)

29. Survey : Surveys are conducted in areas where the registration method is not effective or not functioning properly

30. Sample registration system The field investigation consists of continuous enumeration of births and deaths by a resident part-time enumerator, generally a teacher followed by an independent survey every six months by an official. The data obtained through these operations are matched Hospital records Epidemiological surveillance Disease registers

31. uses The vital statistics help us in understanding how the population profile of a country or a region within the country is changing. 2) The estimation of population trends and projections help the policy planners & administrators for better planning and evaluation of economic and social development programmers. The mortality statistics help us to improve the health conditions of the communities.

32. Neonatal mortality rate (per 1000 live births) Rationale for use Neonatal deaths account for a large proportion of child deaths. Mortality during the neonatal period is considered to be a useful indicator of maternal and newborn health and care

33. Definition Number of deaths during the first 28 completed days of life per 1000 live births in a given year or period .it is of two types early neonatal deaths- occurring during the first 7 days of life late neonatal deaths- occurring after the 7th day but before the 28th completed day of life.

34. Calculation Number of deaths of children under 28 days of age in a year × 1000 Total live births in a same year

35. Maternal mortality The death of a woman while pregnant or within 42 days of termination of pregnancy, irrespective of the duration and site of the pregnancy, from any cause related to or aggravated by the pregnancy or its management, but not from accidental or incidental

36. Calculation Total no. of deaths of women due to complications of pregnancy ,childbirth or within 42 days of delivery from puerperal causes in an area during a given period × 1000 Total number of live births in the same area & year

37. bibliography Park k.; “Textbook of preventive and social medicine”; edition 21 st ; published by m/s banarsidas bhanot publishers; page 850,858. Gulani k. K, community health nursing principles & practises,1 st edition, published by pd11-12b,vishaka enclave, pitampura , delhi-110034.