(i) As the town expands, it mounts more pressure on transport system, water supplies, sewage and profuse disposal.
(ii) The overall development creates problems like air pollution, water pollution, traffic congestion and noise pollution etc.,
(iii) This disturbed environment affects the human beings as mental illness, heart troubles, breathing problems etc.

The natural pollutants are volcanic eruptions, wind erosion, pollen disposal, evaporation of organic compounds and radioactive elements etc.,

(i) Forest Management seeks to achieve a balance between the society's increasing demands for forest products, its benefits and the preservation of forest health and diversity too.
(ii) This balance is critical to the survival of forests and to the prosperity of forest dependent communities.

(i) In ancient Greek, 'demos' means people and 'graphis' means study of measurement.
(ii) So 'Demography' is the statistical study of human population.

Environment can be classified as
(a) Natural Environment
(b) Human Environment and
(e) Man Made Environment

(i) Many people move to urban areas primarily because cities promise more jobs better schools for poor's children and diverse income opportunities then subsistence forming in rural areas.
(ii) Urbanization drives economic growth and causes people to seek working and investment opportunities in urban areas.
(iii) Local governments are unable to manage urbanisation and migrant workers without an affordable place to live in, dwell in slums.
(iv) The VN.Habitat reports that 43% of urban population in developing countries and 78% of those in the least developed countries are slum dwellers.
(v) Lack of affordable low cost housing and poor planning encourages the supply side of slums.
(vi) Some of the slums in to-days world are a product of urbanisation brought by colonialism.
(vii) Urban poverty, encourages the formation and demand for slums.
(viii) Major natural disasters in poor nations often lead to migration of disaster affected form his to unaffiliated areas, the creation of temporary tent city and slums.

(i) The modem technology applied to extract oil and gas while fracturing the rocks artificially with the use of pressurized liquid is called fracking.
(ii) Fracking fluid is a mixture of water, sand and thickening agents.
(iii) The first successful implementation of the process was done in 1950.
(iv) Methane is one of the most important chemicals used in fracking process.
(v) It is estimated that four percent of methane escapes into the atmosphere during extraction.
(vi) Methane is 25 times stronger than carbon di-oxide in terms of trapping heat.
(vii) The spills of this gas is detrimental to the air quality of the surrounding fracking sites
(viii) Pollutants decrease the availability of clean air for workers and local residents

(i) Ozone is a poisonous gas made up of molecules consisting of three oxygen atoms (03). This gas is extremely rare in the atmosphere, representing just three out of every 10 million molecules.
(ii) The ozone layer is not really a layer at all, but has become known as such because most ozone particles are scattered between 19 and 30 kilometre up in the earth's atmosphere, in a region called the stratosphere.
(iii) Ozone layer in the atmosphere absorbs most of the harmful ultraviolet radiation from the sun.
(iv) It also screens out the deadly UV-C radiation the ozone shield is this essential to protect life.

(i) Urban is the term related to cities and towns where people are primarily engaged in non-agricultural activities.
(ii) The factors responsible for urbanization are better employment opportunities, suitable conditions for business, education, transport, etc.
(iii) Urban centres are classified as towns, cities, metropolitan cities, mega cities, conurbation, etc., depending on the size and services available and functions rendered to it.
(a) Town: A town is generally larger than a village, but smaller than a city. It has a population of less than 1 lakh. E.g: Arakkonam.
(b) City: Cities are much larger than towns and have a greater number of economic functions. The population in cities are estimated to be more than 1 lakh. E.g: Coimbatore
(c) Metropolitan Cities: Cities accommodating population between 10 lakhs and 50 lakhs are metropolitan cities. E.g: Madurai
(d) Mega cities: Cities with more than 50 lakh population are called Megacities. E.g: Chennai
(e) Conurbation: A conurbation is a region comprising of a number of cities, large towns and other urban areas. E.g: Delhi

(i) Migration is defined as the permanent or semi-permanent change of home of an individual or a group of people over a significant distance from their place of birth.
(ii) The causes of migration may be physical (climate, drought, flood, earthquake, volcanic eruption, epidemics etc.), social inequalities, economic opportunities, technology, education, cultural clashes, war or political issues.
(iii) There are two types of migration:
(a) Internal Migration
The movement of people within a country i.e. between states, districts, villages, etc is called as Internal migration.
(b) International Migration
The movement of people from one country to another, across international borders is called as International migration.

(i) A settlement pattern refers to the way that buildings and houses are distributed in a rural settlement.
(ii) Settlement patterns are of interest to geographers, historians and anthropologists for the insight they offer in how a community has developed over time.
Linear : In a linear settlement pattern, the buildings are arranged in lines. These lines often follow the route of a road or body of water.
Dispersed : In a dispersed settlement pattern, the buildings are scattered over a wide area. Dispersed settlement patterns are often associated with agricultural activity and are frequently surrounded by farmland.
Nucleated: In a nucleated settlement pattern, the buildings are grouped around a central core. Nucleated settlement patterns are usually associated with patterns of agriculture in which the settlement is surrounded two or three fields, and each field divided into strips that were formed b individual farmers.