Geography: 2015: CBSE: [All India]: Set – II

Sources of water pollutants created by humans:
i. Sewage disposal and urban run-off
ii. Toxic effluents from industries

Golden Quadrilateral comprises construction of 5,846 km long 4/6 lane, high density traffic corridor to connect India’s four big metro cities of Delhi, Mumbai, Chennai and Kolkata. With the construction of Golden Quadrilateral, the time, distance and cost of movement among the mega cities of India will be considerably minimised.

Factors that helped in the development of ancient towns are:
i. Religion
ii. Culture

People engaged in primary activities are called red collar workers due to the outdoor nature of their work.

Motorways are called ‘autobahns’ in Germany.

Characteristics of sub-urbanisation:
i. People move away from congested urban areas to cleaner areas outside the city.
ii. Everyday thousands of people commute from their homes in the suburbs to their workplaces in the city.

Density of population is the ratio between the numbers of people to the size of land.

Density of Population = Population/Area

Population size is an important criteria used by most countries to define urban areas.
i. The lower limit of the population size for the settlement to be designated as urban is 1,500 in Colombia, 2,000 in Argentina and Portugal, 2,500 in USA and Thailand, 5000 in India, 30,000 in Japan.
ii. In Denmark, Sweden and Finland all places with a population size of 250 persons are called urban.
iii. The minimum population for a city is 300 in Iceland, where as in Canada and Venezuela, it is 1,000 persons.

Knowledge about nature is extremely important to develop technology and technology loosens the shackles of environment on human beings.

Many important discoveries and inventions were done because of the knowledge of nature.
i. Understanding of concepts of friction and heat helped us discover fire.
ii. Understanding of the secrets of DNA and genetics enabled us to conquer many diseases.
iii. The laws of aerodynamics are used to develop faster planes.

Three features of semi-clustered rural settlements of India are:
a. They may result from tendency of clustering in a restricted area of dispersed settlement.
b. They may also result from segregation or fragmentation of a large compact village.
c. Some people of the village society choose or are forced to live a little away from the main cluster or village.