## Population Density

Subject: Enviroment Population and Health

#### Overview

The age-sex composition of the population can be also expressed interms of the pyramid. Population pyramid can be defined as the graphical presentation of the age-sex composition of the population and population density ca be defined as the total number of people living in a per unit are or unit volume. This note provides information about population pyramid and population density by ecological region, development region and by place of residence.
##### Population Density

Population Pyramid

Population composition by age and sex, Nepal, 2011 AD.The age-sex composition of the population can be also expressed in terms of the pyramid. Population pyramid can be defined as the graphical presentation of the age-sex composition of the population. In population pyramid,

the percentage of the male population is presented in a horizontal bar on the right side and the percentage of the female population is also presented in the horizontal bar, but on the left side. Here, the height of the pyramid represents the age. There are various types of the pyramid. The broad-based pyramid represents the age-sex composition of developing countries with high rate population growth and fertility whereas narrow-based pyramid represents developed countries with low fertility and low population growth. Now, let us draw population pyramid from the data of population composition by age and sex of Nepal 2014 AD.

#### Population density

Population density can be defined as the total number of people living per unit or unit volume. We can also say, population density is the population per unit area or per unit volume. It is used to measure the pressure of population on land. Population density can be calculated by dividing the total population of a place by the total land area of that place.Population Density

Population density = $\frac{P}{A}$
Where,
P= Population of a place
A= Total land- area of the place

Population density is greatly affected by the environmental aspects like land, water, land topography, climate, vegetation etc. It is also socio- economic factors like industries, education, trade etc. The density of population is more in that area where there is fertile land, education, health, security, industrial centers, highways etc. and density of population is less in those areas where there is no facilities or fewer facilities like education, health, no highways and industrial centers etc. For example, the population density of Mustang is less than the population density of Kathmandu, Nepal. As Kathmandu is the Capital city and Mustang is a village where there is no roads, electricity, education, and health.

Population Density by Ecological Region

Nepal is geographically divided into three development region. They are mountain region, hilly region, and terai region. In these areas, the population is increasing day by day. The most densely populated region is terai region then hilly region and the mountain region. The population density of this three development region of Nepal is given below,

 Ecological Zones 1991 2001 2011 Mountain 28 33 34 Hill 137 167 186 Terai 254 330 392 Nepal 126 157 180

The given table shows that the density of population in the mountain region and hilly region is increasing very slowly. But, the population density of terai region is increasing very rapidly. The population density of terai has increased from 254 persons per square kilometer to 392 persons per square kilometer whereas the population density of mountain has increased from only 28 persons per square kilometer to 34 persons per square kilometer in 2011 AD. The population density of hilly region has increased from 137 persons per square kilometer to 186 persons per square kilometer. The density of population in mountain region is very low because there are fewer facilities, no fertile soil, difficult topography, and less road connection. Similarly, the population density of terai region is more because there are better facilities, fertile soil, good connection of road, a large number of industries etc.

Population Density by Development Region

There are five development regions in Nepal. They are Farwestern development region, Midwestern development region, Western development region, Central development region and Eastern development region. The development region with highest population density is Central development region. The population of central development region is increasing vastly in comparison to other development regions. The population density of central development region has increased from 226 in 1991 AD to 352 per square kilometer in 2011 AD. This is because there are better facilities in central development region than other development regions. The development region with least population density is Midwestern development region. Though, the mid- western development region is the largest development region of Nepal, the population of mid- western development region is very low. This is because, there is less infrastructure for development, less socio- economic activities and less fertile land with less rainfall. The given table below shows the population density of five development regions of Nepal from 1991 to 2011 AD.

 Development Regions 1991 2001 2011 Eastern 156 188 204 Central 226 293 352 Western 128 155 168 Mid- western 57 71 84 Far western 89 122 131 Nepal 126 157 180

Population Density by Place of Residence

The population density by place of residence is increasing day by day. The population density of both of the rural and urban area is increasing. The population density of rural area has increased from 138 to 153-kilometer square. Similarly, the population density of urban was 185 kilometer square in 2001 AD.

 Place 2001 2011 Rural 138 153 Urban 985 1,380 Nepal 157 180

##### Things to remember
• Population pyramid can be defined as the graphical presentation of the age-sex composition of the population.
• Population density ca be defined as the total number of people living in a per unit are or unit volume.
• Population density can be calculated by, Population density = $\frac{P}{A}$.
• The development region with highest population density is central development density.
• The ecological region with highest population density is hilly region.
• The reasons of high population density in the terai region is better facilities and more industries.
• The population density of rural area has increased from 138 km square.
• It includes every relationship which established among the people.
• There can be more than one community in a society. Community smaller than society.
• It is a network of social relationships which cannot see or touched.
• common interests and common objectives are not necessary for society.
##### Population Pyramids - The basics
Any two factors that affect the population density of particular area is land topography and transportation.
Population density is the total number of people living in a standard unit area.
The population density of Mountain region according to 2011 AD census is 34.
The population density of Terai region according to 2001 AD census is 167.
The population density of Hill region according to 2011 AD census is 392.
The population density of Eastern Development Region of Nepal according to 2011 AD census is 204.
The population density of Central Development Region of Nepal in 2001 AD census was 293.
The population density of rural area of Nepal according to 2011 AD census is 153.
The population density of urban area of Nepal according to 2011 AD census is 1,380.

Population density is the average numbers of people residing pere square kilometerarea. It is calculated by dividing the total population of a country or place by its total area . The situation of population density according to geographical region in Nepal are as follows :

• Mountain regions
• Hill region
• Terai region

The population is not found to have distributed equally in a different geographical region and administrative areas . The statisticsof the distributionof the population shows how the population has been distributed in different areas of the nation . Population statistics makes it easy for the government , planners or policy makers and administrators to develop policies , plans and programmes and implement them . It is also helpful in researchand studies for researchers . Thus , the statistics of distribution of population is necessary and very important .

In the following conditions the population increases :

• If the birth rate is higher than death rate .
• If the number of children and alsoof the old is more .
• If the medical facility suddenly increases and decreases the birth .

In the following conditions the population decrease :

• If the birth rate highly decreases .
• If the death rate increases .
• If medical care fail to treat the people.