Lesson 2 Human Population Dynamics/Issues PDF

North Eastern Mindanao State University Formerly Surigao del Sur State University Bislig Campus Maharlika, Bislig City, Surigao del Sur Lesson 2 Human Population Dynamics/Issues Objectives At the...

North Eastern Mindanao State University Formerly Surigao del Sur State University Bislig Campus Maharlika, Bislig City, Surigao del Sur Lesson 2 Human Population Dynamics/Issues Objectives At the end of this lesson, you should be able to: 1. defined demography and demographic measures. 2. computed for the arithmetic population growth. 3. gathered, organized, and interpreted human population dynamics data (age- sex structure, density, and distribution) Introduction Human population trends are necessary because they play a vital role in determining the environmental impact of human activities. Rising population can be attributed to certain parameters such as the demographic and dynamical factors of the population. Birth and death rates, and to include migrants, may trigger the dramatic expansion of the population. In this lesson, you will get to look into certain demographical measures that are contributory to the rate of growth of the population. Dynamical data such as age, sex structure, density, and distribution of human population in certain locality will be explored. You may also learn to compute the population growth rate. Demography is the scientific study of human populations. It includes population processes that change population size such as births, deaths, and migration. It encompasses the size, distribution, and structure of the population. The population characteristics may allow predictions of the future, more so it may establish relationships with factors such as economic, social, and cultural. Today you will be able to encounter parameters, known as demographic measures, necessary in the study of human population dynamics. DEMOGRAPHIC MEASURES Population size increases because of births and immigration and decreases through deaths and emigration. Human population of countries and cities grow or decline through the interplay of three factors: births (fertility), deaths (mortality), and migration (immigration and emigration). Population change of an area can be computed by subtracting the number of people leaving a population (through death and emigration) from the number entering it (through birth and immigration) during a specified period of time (usually one year). 𝑃𝑜𝑝𝑢𝑙𝑎𝑡𝑖𝑜𝑛 𝐶ℎ𝑎𝑛𝑔𝑒 = (𝐵𝑖𝑟𝑡ℎ𝑠 + 𝐼𝑚𝑚𝑖𝑔𝑟𝑎𝑡𝑖𝑜𝑛) − (𝐷𝑒𝑎𝑡ℎ𝑠 + 𝐸𝑚𝑖𝑔𝑟𝑎𝑡𝑖𝑜𝑛) MST-PEE (People and Earth Ecosystem) I by Rodrigo Sumuob  North Eastern Mindanao State University Formerly Surigao del Sur State University Bislig Campus Maharlika, Bislig City, Surigao del Sur When births plus immigration exceeds deaths and emigration, population increases, when the reverse happens, population declines. BIRTH RATE & DEATH RATE Instead of using the total numbers of births and deaths per year, population experts (demographers) use the birth rate, or crude birth rate, and death rate, or crude death rate. Birth rate is the number of live births in 1 year per 1,000 people in the population. According to the International Encyclopedia of Public Health (2008), birth rates are the crucial determinant of population growth (or decline) and age structure of populations have profound socioeconomic implications. Robey, B. (1993) stated that in the mid-60s women in Asia, Africa, and Latin America gave birth to an average of six children. In the 1990s, the average is about four – a drop of one-third. Then eventually, it dropped having an average of 2.1. The number of children per couple is just enough to replace them – thus, a zero-population growth. However, Robey mentioned that despite the remarkable decline in birth rates, population continue to grow more rapidly for the past years because the number of women of childbearing age is rising which resulted to high birth rates. DEATH RATE Death rate is the number of deaths in 1 year per 1,000 people in the population. Miller & Spoolman (2009) mentioned that rapid growth of the world’s population over the past 100 years is not primarily the result of the rise in the crude birth rate. Developing countries, primarily, had declined in their crude death rates because people are living longer and fewer infants die due to increase in food supplies and distribution, better nutrition, medical advances, improved sanitation, and safer water supplies. Meaning, life expectancy had increased, from 48 years to 68 years on the average, and infant mortality had decreased in number. Infant mortality is viewed as one of the best indicators of society’s quality of life, since it reflects the country’s general level of nutrition and health care. FERTILITY RATE Another measurement used in population studies is fertility rate, the number of children born to a woman during her lifetime. There are two types of fertility rates that affect a country’s population size and growth rate. 1. Replacement-level fertility rate, is the average number of children that couples in a population must bear to replace themselves. It is slightly higher than two children per couple (2.1 in developed countries and as high as 2.5 in some developing countries), mostly because some children die before reaching their reproductive years. 2. Total fertility rate (TFR), is the average number of children born to women in a population during their reproductive years. This factor plays a key role in MST-PEE (People and Earth Ecosystem) I by Rodrigo Sumuob  North Eastern Mindanao State University Formerly Surigao del Sur State University Bislig Campus Maharlika, Bislig City, Surigao del Sur determining population size. The average fertility rate has been declining. In 2008, the average global TFR was 2.6 children per woman: 1.6 in developed countries (down from 2.5 in 1950) and 2.8 in developing countries (down from 6.5 in 1950). Although the decline in TFR in developing countries is impressive, the TFR remains far above the replacement level of 2.1, not low enough to stabilize the world’s population in the near future. Why has the world’s exponential rate of population growth slowed down in the last few decades? What would have to happen for the world’s population to stop growing? POPULATION GROWTH RATE Population growth rate (r) is the net number of people added to a population in 1 year per 1000 people already in the population. The following legend will be used in this part of the lesson. Legend: 𝑃𝑜 = 𝑝𝑜𝑝𝑢𝑙𝑎𝑡𝑖𝑜𝑛 𝑎𝑡 𝑡ℎ𝑒 𝑠𝑡𝑎𝑟𝑡, 𝑒. 𝑔. 𝑦𝑒𝑎𝑟 𝑧𝑒𝑟𝑜 𝑃𝑛 = 𝑝𝑜𝑝𝑢𝑙𝑎𝑡𝑖𝑜𝑛 𝑎𝑡 𝑡ℎ𝑒 𝑒𝑛𝑑, 𝑒. 𝑔. 𝑎𝑓𝑡𝑒𝑟 𝑛 𝑛 = 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑖𝑛𝑡𝑒𝑟𝑣𝑎𝑙𝑠 (𝑒. 𝑔. 𝑦𝑒𝑎𝑟𝑠) 𝑏𝑒𝑡𝑤𝑒𝑒𝑛 𝑃𝑜 𝑎𝑛𝑑 Pn For ease in computing for the population growth rate, may we recall the following mathematical formulas: HUMAN POPULATION DENSITY Population density is a measurement of the number of people in an area. It is calculated by dividing the number of people by the area of the land (Internet Geography, 2020). The Population density given in the picture to your right is the average population density of the entire Philippines. This is computed by using this formula: MST-PEE (People and Earth Ecosystem) I by Rodrigo Sumuob  North Eastern Mindanao State University Formerly Surigao del Sur State University Bislig Campus Maharlika, Bislig City, Surigao del Sur If the total population of the Philippines in 2015 is 100, 981, 437 people and the land area is 300,000 km². Using the formula give above, you will get a population density equal to 336.60 people/km² ̴337 people/km². Source: https://psa.gov.ph/content/philippine-populationdensity-based-2015-census-population Given the data shown in the picture above, what can be say about the population density of the Philippines? The population density of the Philippines is increasing. In year 2000 there were 255 people residing in every square kilometer (km²) of land. Furthermore, the data shows that there are a greater number of people per km² in the year 2015 than in the year 2010. This represents an increase of 29 persons per km² between 2010 and 2015. The population density, in 2015, of the two regions in the Philippines such as that of the National Capital Region (NCR), whose population density is 20,785 people/km², and that of Cordillera Administrative Region (CAR) is 84 people/km². This may mean that NCR has a greater population density than that of CAR. MST-PEE (People and Earth Ecosystem) I by Rodrigo Sumuob  North Eastern Mindanao State University Formerly Surigao del Sur State University Bislig Campus Maharlika, Bislig City, Surigao del Sur Why is it that density in NCR different from that in CAR? The answer to this question may come after we have discussed the next topic, human population distribution. POPULATION DISTRIBUTION Population distribution is the spread of people across the world. The world’s population is spread unevenly across the globe with concentrations of large numbers of people living in the same area. The world as a whole has more ‘empty’ areas than ‘crowded’ areas. There are several physical and human factors to explain this. There are factors, both Physical and Human, that are contributory to the distribution of the population. The table below will show you these factors that contributes to the uneven distribution of the population. HIGH POPULATION PHYSICAL FACTORS LOW POPULATION DENSITY DENSITY More people tend to Less people live in high Topography (Altitude and reside in low land which is land, like in mountainous Shape of the land) flat. areas. Areas rich in resources Areas with few resources Resources (like coal, oil, fishing) are are sparsely populated. densely populated. Areas with temperate Areas with extreme climates tend to be climates of hot and cold densely populated, are sparsely populated. It Climate enough rain and heat to is basically difficult to grow crops and grow crops and conducive for rearing domesticate animals. domesticated animals. HIGH POPULATION HUMAN FACTORS LOW POPULATION DENSITY DENSITY People tend to flock in Unstable government Political countries with stable have lower density as government. people tend to migrate. People wants to live close People in far-flung areas Social to each other for security. are left isolated. Good job opportunities Limited job opportunities may encourage people have lesser residents, Economic to reside, especially in especially in remote and large cities. mountainous areas. MST-PEE (People and Earth Ecosystem) I by Rodrigo Sumuob  North Eastern Mindanao State University Formerly Surigao del Sur State University Bislig Campus Maharlika, Bislig City, Surigao del Sur The population density of the Philippines is high, but the population distribution is uneven. Parts of Metro Manila have population density that is 100 times that of some outlying areas such as the mountainous area of Northern Luzon. Again, another table is presented here to compare and contrast population density and population distribution. POPULATION DENSITY VS. POPULATION DISTRIBUTION Population Density Population Distribution The arrangement of the population in a The measure of the number of people certain area in accordance with that make up the population in a conditions and requirements of the definite area. society. Describes the number of people in a Describes the variability of the spread of particular population inside a unit area the population in a particular area. of land. The entire Greater Manila is reported to The Philippines has a population density contain 22.7 million people which is a of 337 people/km². quarter of the Philippines’ entire population. The last row of the table above shows that the people in the Philippines are not evenly distributed, in fact there is uneven distribution of people in the entire land area. Why is this so? The Philippines is an archipelago which has over than 7,00 islands that has a total area of 300,000 km². Most of the islands are small, only a few are larger ones like Luzon and Mindanao, which accounts for a larger portion of the surface area. While some islands are highly populated than others, the bulk of people are residing in Luzon and Mindanao areas. The distribution of people in the entire Philippines is uneven, a lot are in the Luzon area, most are in the Greater Manila, and in the Mindanao islands, the bulk of people are in Davao City (World Population Review, 2020). AGE AND SEX Age and sex, one of the many demographic variables, are arguably the most important and relevant to demographers. Horiuchi and Preston (cited in Poston, 2005) stated that the interaction of the demographic processes, such as fertility, mortality, migration, and growth, produces the age and sex structure of the population. Reciprocally, this age and sex structure of a population, in itself, affects the interaction of these demographic processes. MST-PEE (People and Earth Ecosystem) I by Rodrigo Sumuob  North Eastern Mindanao State University Formerly Surigao del Sur State University Bislig Campus Maharlika, Bislig City, Surigao del Sur Population Reference Bureau (2019) defines age structure as the proportion of the total population in each age group. Davis & Morduck (cited in Poston, 2005) stated that the distribution of the age groups (infant, young, adult, etc.) and sex (male or female) of the population defines the division of labor in traditional societies. Moreover, Keyfitz & Flieger (cited in Poston, 2005) mentioned that changes in the age distribution of a population have consequences for educational, political, and economic life. SUMMARY Population size increases because of births and immigration and decreases through deaths and emigration. Population change of an area can be computed by subtracting the number of people leaving a population (through death and emigration) from the number entering it (through birth and immigration) during a specified period of time (usually one year). When births plus immigration exceeds deaths and emigration, population increases, when the reverse happens, population declines. Birth rate is the number of live births in 1 year per 1,000 people in the population. Death rate is the number of deaths in 1 year per 1,000 people in the population. There are two types of fertility rates that affect a country’s population size and growth rate. The first type, called the replacement-level fertility rate, is the average number of children that couple in a population must bear to replace themselves. The second type of fertility rate, the total fertility rate (FTR), is the average number of children born to women in a population during their reproductive years. Population growth rate ® is the net number of people added to a population in 1 year per 1000 people already in the population. Population density is a measurement of the number of people in an area. Population distribution describes the variability of the spread of people across the world. Age structure is the proportion of the total population in each age group. Age and sex structure and the demographic processes relates with each other by reciprocity. Reflection 1. As a student, why do you need to learn about the factors that may affect the size of the population? ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ 2. How can you help to slow down human population growth? ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ Cited References: MST-PEE (People and Earth Ecosystem) I by Rodrigo Sumuob  North Eastern Mindanao State University Formerly Surigao del Sur State University Bislig Campus Maharlika, Bislig City, Surigao del Sur International Encyclopedia of Public Health (2008). Birth rate. Retrieved from: https://www.sciencedirect.com/topics/agricultural-and- biologicalsciences/birth-rate Internetgeography.net (2015). Retrieved from: https://www.internetgeography.net/topics/what-is-population-density/ Miller, G. T. & Spoolman, S. E. (2009) Essentials of ecology. Brooks/Cole, Cengage Learning. Philippine Statistics Office (2020). Philippine population density (Based on the 2015 Census Population). Retrieved from: https://psa.gov.ph/content/philippine- population-density-based-2015-censuspopulation Robey, B. (1993). The birth rate decline in developing countries. Sage Journals, 22(4), 221-224. Retrieved from: https://journals.sagepub.com/doi/pdf/10.1177/003072709302200403 Poston, D. (2005). Age and sex. Handbook of population. Retrieved from: https://link.springer.com/chapter/10.1007%2F0-387-23106-4_2 Crossman, A. (2019). Age structure and age pyramids: An overview of the concept and its implications. Retrieved from: https://www.thoughtco.com/age-structure- definition-3026043 MST-PEE (People and Earth Ecosystem) I by Rodrigo Sumuob