Class 10 Environment and Population and Health Solution
Demography
Answer the following questions:
1. What is demography? Explain.
Ans: Demography is the measurement of the population of a specific place in a particular time and their scientific study. Demography means the statistical and mathematical study of population size, regional distribution, composition and population change. Demography can also be stated as the scientific study of human population.
The measure of population growth rate, population doubling time, infant mortality rate, maternal mortality rate, crude birth rate, crude death rate, sex ratio, dependency ratio, etc. From the demographic study of population a clear cut idea about the population situation can be visualized and the plans and policies can be made for the existing population for their progress and development. Therefore demography is very important.
2. Write the major sources of population statistics.
Ans: The major sources of population statistics are as follows:
-Primary Sources
-Census
-Vital registration
-Sample survey
-Administrative records
-Secondary sources
-Organizations and institutions
-Books
-Journals
-Newspaper
3. Is sample survey a good source of population statistics? Justify your answer.
Ans: Sample survey is the source of population statistics in which the population data is obtained by choosing some sample from the country and conducting survey on them. It is the quickest and the easiest way of obtaining the population statistics. Although it is very easy and quick process, this process cannot be stated as the good source of population data. This process may not always give the accurate data about the population because the sample chosen during the survey might not always represent the people from various groups. Sometimes this source of population data might be very good and accurate but the probability of getting inaccurate data is very high in this process. Therefore in my opinion sample survey is not a good source of population data.
4. What are the sources of demographic measures? Explain.
Ans: The sources of demographic measures are as follows:
-Birth
-Death
-Migration
Birth is also the source of demographic measure because from birth following demographic measurement can be done. They are:
-Crude Birth Rate
-General Fertility Rate
-Age Specific Fertility Rate
-Total Fertility Rate
Death is also the source of demographic measure because from death following demographic measurement can be done. They are:
-Crude Death Rate
-Age Specific Death Rate
-Infant Mortality Rate
Migration is a source of demographic measure because from migration following demographic measurements can be done. They are:
-In Migration Rate
-Out Migration Rate
-Net Migration Rate
-Gross Migration Rate
5. Define crude birth rate. Write the formula of measuring crude birth rate.
Ans: Crude Birth Rate is the total number of living infants born within a year in a place or country by the total number of midyear population and multiplied by thousand. Midyear population is either the population of July 1 or the population of January 1 and December last divided by 2. The formula of measuring crude birth rate is as follows:
CBR = $\frac{{{\rm{Total\: number\: of\: live\: births\: in\: a\: year}}}}{{{\rm{Mid}} - {\rm{year\: population}}}}{\rm{*}}100{\rm{\: }}$
6. What do you mean by age specific fertility rate? Explain its importance and necessity.
Ans: Age specific fertility rate is the rate of fertility in which the birth of the child of the woman in a certain age group is divided by the mid year population of the women age group and multiplied by thousand. Age specific fertility rate is important because this data shows the most active age group to give birth and the most inactive group in the child bearing process. It is necessary because this data also provides idea which is the most fertile, suitable and safe period to give birth to the child.
7. How is age specific death rate measured? Explain and write the formula of measuring age specific death rate.
Ans: Age specific death rate is measured by dividing the total number of deaths in a specific age group by the total midyear population of the age group and multiplying by thousand. Age specific death rate is measured by using the following formula:
ASDR = $\frac{{{\rm{Number\: of\: death\: births\: in\: a\: particular\: age\: group}}}}{{{\rm{Total\: mid}} - {\rm{year\: population\: of\: that\: age\: group}}}}{\rm{X\: }}1000$
8. What is migration? How does it affect the population distribution of a place?
Ans: Migration is the process of transferring of people from one place to another place for permanent settlement. Migration affects the distribution of population of the place. The distribution of the population of the particular place will be affected because due to urbanization the people will migrate to urban areas which will definitely increase the population of that place. Similarly the population of the urban areas will decrease accordingly. In this way migration creates uneven distribution of population. So migration is not a good factor in population because people do not migrate to rural areas where there are ample natural resources. The proper exploitation of natural resources is decreasing due to migration.
9. What are the biological factors that affect birth? Explain any three of them with examples.
Ans: There are various biological factors affecting birth. The biological factors affecting birth are heredity, age, ovulation, lactation, miscarriage and health. Any three of them are described below:
-Heredity: Heredity affects birth because the problems related to reproductive organs; reproductive process and infection of sexually transmitted diseases have negative effects on fertility.
-Age: People become fecund after they reach certain age of maturity. Girls become fecund after they reach the age of 14-15 and they can conceive upto the age of 49. Therefore age is the biological factor affecting birth.
-Health: Healthy man has healthy life and their child bearing capacity is affected by their health also. Therefore health is the biological factor affecting birth.
10. Make a list of the factors affecting death rate and explain any four of them.
Ans: The factors affecting death rate are heredity, sex, senescence, diseases, level of nutrition, health services and facilities and health education. Any four of them are described below:
-Heredity: Longevity of life is characteristics of heredity. Long life is attributed to heredity. Some people whose forefather lived for a long period of time are also living longer. Longevity of human life depends on the environment where they are born and brought up.
-Sex: It has been found that female live longer than males. This trend has not only been seen in a certain countries but everywhere in the world. It has also been found that infant mortality rate for boys are higher than for girls.
-Diseases: This is the age of science and technology. In spite of great development of science and technology, scientists have not been able to prevent death. People have to lose their life being the victim of infectious, fatal and hereditary diseases.
-Level of nutrition: Food is one of the bases of life. Continuous intake of nutritious food is as important as air and water for the survival of life. Lack of nutritious food makes people fight against diseases which ultimately take the life towards death.
11. What are the factors affecting migration? Explain with examples.
Ans: The factors affecting migration are age, sex, family status and occupation. They are described as follows:
-Age: In both of the internal and international migration, young age people migrate more than the people of other age groups. One of the reasons behind this is that young people can easily adapt in a new place, society or climate. The number of migrants from children, old age groups is very low in comparison to the young and economically active population.
-Sex: Internally, female migrate more than males because they have to leave their parents home and go to their husband's home after they get married. Males migrate in search of work.
-Family status: The status of a person also affects migration. Young and unmarried people migrate more than the married and people of other age group.
-Occupation: People have to migrate from their birth place to new place for occupation. By the nature of work people do migrate from one place to another place.
12. Which aspects of our life are adversely affected by the migration from one place to another? Explain in short.
Ans: Various aspects of migration are affected adversely by the migration of people from one place to another. The areas affected by migration are environmental aspect, economic aspect and health and social aspect.
Environmental aspect: Migration has direct effects on environmental aspects. The problems of the destruction of natural resources, environmental degradation and natural imbalance and pollution are increasing. Due to the misuse of natural resources and excessive deforestation, the balance between human being and environment has been affected. The disturbance in the natural balance has created pollution of different kinds in our surroundings.
Economic aspect: because of the flow of migration from Hills to Terai has created shortage of competent, efficient and active manpower in the hilly region. The effects have been seen in the development and construction works in the hilly areas. Most of the immigrants in Nepal are skilled workers, laborers and businessman. There is a competition between the immigrants and the local people because of high level skills and low rate of wages. The immigrant workers have strong control over the labor market of the trade and industries of Nepal. This has developed a situation of monopoly of immigrants in Nepal. All the wage, profit and properties earned by immigrants are sent to their own countries. This has adverse effects on the economy of the country.
Health and social aspect: Different studies have shown that the migrants from the Hills to the Terai and from the rural areas to urban areas are mainly young males and the educated persons. Effects of migration are the emergence of several of social disorders and crimes. The mentality and concept of migrants may be different from that of local people. This may be because of the differences in caste, language, culture and so on. These factors may lead to conflicts, tensions and crimes in the mixed society of migrants and the local people.
2. Write short notes on:
1. Demographic measure
The measurement of the three components of fertility, mortality and migration are necessary for the proper analysis of population. The rates of fertility, mortality and migration are used for measuring population changes using different formula. Necessary figures are calculated from these measures. We can analyze the changes in size, composition and distribution of population. Moreover, the trend of the changes of population in the future can also be analyzed.
The fertility rate can be obtained in the following ways:
-Crude Birth Rate
-General Fertility Rate
-Age Specific Fertility Rate
-Total Fertility Rate
The mortality rate can be obtained in the following ways:
-Crude Death Rate
-Age Specific Death Rate
-Infant Mortality Rate
The migration rate can be obtained in the following ways:
-In Migration Rate
-Out Migration Rate
-Net Migration Rate
-Gross Migration Rate
2. Administrative records
Administrative records are one of the sources of obtaining the population data. It is the primary source of population data. These records cannot cover the whole population of the country. The administrative offices and the agencies collect and keep the records of data necessary for the official use. The data obtained by the records kept by those officers are useful in recording the vital events and sample surveys. Specific data related to the life of the people can be obtained from voter's list, records of trade unions, records of citizenship, telephone directory, records maintained by non-government organizations.
3. Total fertility rate
Total fertility rate refers to the average numbers of infants born to a women or a age group of women during the period of 15 to 49 years. Total fertility rate is derived from the age specific fertility rates. Total fertility rate is calculated by multiplying the sum of the age specific fertility rate with 5 and dividing the result with 1000. Total fertility rate is expressed in terms of the number of ever born child per women. The formula for calculating total fertility rate is:
TFR = $\frac{{ \in {\rm{ASFR*Age\: interval\: of\: }}5}}{{1000}}$
4. Infant mortality rate
Infant mortality rate is taken as an important indicator of age specific death rate. The death rate out of 0-1 year's age group in population is the highest of each country. In a country where infant mortality rate is high the economic, social and health conditions of the country is regarded to be poor. Infant mortality rate is calculated by dividing the number of deaths of the infants by the numbers of total live births of infants and multiplying by 1000. The formula can be written as follows:
IMR = $\frac{{{\rm{Number\: of\: death\: of\: infants\: in\: a\: year\: X\: }}1000}}{{1000}}$
5. Net migration rate
The difference between the number of people in migrants and the number of out migrants is called net migration rate. The following formula can be used to calculate the net migration rate:
NMR = $\frac{{\left( {{\rm{Number\: of\: in\: migrants}} - {\rm{Number\: of\: out\: migrants}}} \right){\rm{\: X\: }}1000}}{{{\rm{Total\: midyear\: population\: of\: that\: year}}}}$
6. Doubling time of population
If the population growth rate is one percentage then the population of the certain place will double in seventy years. Population doubling time can be obtained by dividing the population growth rate by 70. The formula for calculating doubling time of population can be written as follows:
${\rm{PDF}} = \frac{{{\rm{population\: Growth\: Rate}}}}{{70}}$
3. Differentiate between:
1. Demographic components and Demographic processes
Demographic components |
Demographic processes |
Birth, death and migration are the demographic components. The change in population size of any place or region mainly depends upon birth, death and migration. |
Fertility, mortality and migration are the demographic processes. The demographic processes of fertility, mortality and migration bring change in the size, composition and distribution of population. |
2. Census and Sample survey
Census |
Sample survey |
Census is the total process of collecting, compiling, analyzing and publishing or otherwise dissimilating demographic, economic or social data pertaining to the people of the country or well delineated part of the country. |
The primary source of population data in which the samples are chosen from various fronts and data is collected is called sample survey. It is the easiest method to collect the population data. |
Census requires long time to be done for the population data. |
Sample survey requires less time than the census to collect the population data. |
Census is more accurate than sample survey. |
The result of sample survey may not be accurate all the time. |
3. Fertility and Fecundity
Fertility |
Fecundity |
Fertility is the actual birth performance of woman during her reproductive period. |
Fecundity is the psychological notion or the actual birth giving capacity of a woman. |
4. General fertility rate and Age specific fertility rate
General fertility rate |
Age specific fertility rate
|
General fertility rate is the total number of birth divided by the total midyear population of the particular place multiplied by thousand. |
Age specific fertility rate is the total number of births of the specific age group divided by the population of the age group multiplied by thousand.
|
The formula is: GFR=(Total live birth X 1000) / Mid- year population of women(15-49) |
The formula is: GFR=(Total live birth of a age group X 1000) / Mid- year population of age group |
5. In-migration rate and Out-migration rate
In-migration rate |
Out-migration rate |
The rate of number of people migrating to certain place is called the in-migration rate of that place. |
The rate of number of people migrating from certain place is called the out-migration rate of that place. |
The formula is: IMR= (No. of in-migrants X 1000) / Midyear population |
The formula is: OMR= (No. of out-migrants X 1000) / Midyear population |
6. Population growth rate and Rate of natural increase
Population growth rate |
Rate of natural increase |
The sum of the rate of natural increase of population and the rate of in-migration is the population growth rate. |
The rate in which the population increases because of more birth and less death is called the rate of natural increase. |
The formula is: RNI= (CBR-CDR) X 100 / 1000 |
The formula is: PGR=(CBR-CDR +-NMR)X 100 / 1000 |