Introduction:
If we see the people across different regions of the world, we find that they look quite different from each other but their basic needs are the same i.e. food, clothing and shelter.
The difference in looks is to some extent due to the climatic factors and environmental conditions.
The differences in looks may be difference in skin colour, hair colour and type; facial features, height, weight, etc.
The tropical and the sub tropical regions:
The tropics have been historically defined as lying between the Tropic of Cancer and Tropic of Capricorn, located at 23.45° north and south latitude respectively.
The literal meaning of the word ‘sub’ is ‘under’.
The subtropics are geographic and climate zones located roughly between the 23.5° and 38° parallels in both hemispheres.
Thus, the subtropical regions lie beyond the Tropic of Cancer and Tropic of Capricorn in both hemispheres.
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THE TROPICAL REGION:
Life in the Amazon basin:
The river Amazon flows through the mountains (Andes Mountains) to the west of the tropical region and reaches the Atlantic Ocean to the east.
Numerous tributaries join the river to form the basin.
The river basin drains portions of Brazil, parts of Peru, Bolivia, Ecuador, Columbia and a small part of Venezuela.
Some of the detailed features of this region are as under:
Climate:
The Amazon Basin stretches directly on the equator and is characterized by hot and wet climate throughout the year.
It rains almost every day here.
The temperature during the day is very high; the humidity is also high during the day.
The temperature at night decreases, but there is high humidity.
Hence, both the day and night are almost equally hot and humid.
Rainforests:
Since it rains heavily in this region, the forests are very thick.
The forests are so dense that sunlight does not reach the land.
Hence the land is damp and dark.
Consequently, only shade tolerant vegetation can grow here.
Orchids and bromeliads grow here.
Birds:
Toucans, humming birds, birds of paradise are found here.
The brilliantly coloured plumage and oversized bills for eating; make these birds very different from the birds commonly seen in India.
These birds also make loud sounds.
Animals:
Monkeys, sloths, and ant eating tapirs are found here.
Species of reptiles and snakes are also found here.
Crocodiles, snakes and pythons are in plenty.
Some of the species of snakes are anaconda and boa constrictor.
Many insects and species of fishes (including the flesh eating Piranha fish) are found here.
People of the rainforests:
People grow most of their food in small areas after clearing the trees in the forest.
Men hunt and fish; and women take care of the crops.
Since hunting and fishing are uncertain, farming is necessary to ensure availability of food.
Tapioca, pineapple and sweet potato are the main crops.
Manioc or cassava is the staple food.
It grows underground; like potato.
Queen ants and egg sacs are also eaten by the people of Amazon rainforests.
Cash crops like coffee, maize and cocoa are also grown.
They practice ‘slash and burn agriculture’.
The rainforests provide a lot of wood for the houses.
People live in thatched houses shaped like beehives.
Apartment – like houses called ‘Maloca’ with a steeply slanting roof are also found.
With passage of time, the life of the people of this area is slowly changing.
Previously, navigating through the river was the only means of reaching the heart of the forest. The Trans Amazon highway was made in 1970.
It made all parts of the rainforest accessible.
Aircrafts and helicopters are used to reach all previously inaccessible places.
These changes forced the indigenous people to relocate.
But they still continue with their distinctive way of farming.
A gradual destruction of the biologically diverse rainforests is happening because of the developmental activities.
A large area of the rainforest has been disappearing in the Amazon basin, thereby leading to a serious implication which is: washing away of the top layer of the soil and making the land barren.
Slash and burn:
It is a way of cultivating land in which farmers cultivate a piece of land by slashing/cutting the trees and bushes.
These are then burnt, which releases the nutrients in the soil.
New crops are grown in this cleared field for a few years.
Since the fertility of the land is lost after a few years of cultivation, the used land is abandoned and a new set of land is cleared for cultivation.
In the mean time young trees grow in the old field.
In this way soil fertility is restored.
People can then return to the old land and start cultivating it again.
THE SUB-TROPICAL REGION:
The Ganga-Brahmaputra basin:
The Brahmaputra River originates on the Angsi glacier on the northern side of the Himalayas in Burang country of the Tibet.
Name of Brahmaputra in the other countries are Yarlung Tsangpo in Tibet , Dihang in China , Jamuna in Bangladesh ,
The Ganga-Brahmaputra basin is formed in the Indian subcontinent by the tributaries of the rivers Ganga and Brahmaputra.
The basin lies in the sub-tropical region that is situated “between” 10 degree north to 30 degree north latitudes.
Some of the tributaries of the river Ganga are – the Ghaghra, the Son, the Kosi, the Chambal and the Gandak.
The main features of this basin are the plains of the Ganga and the Brahmaputra, the mountains and the foothills of the Himalayas and the Sundarbans delta.
Ox-bow lakes dot the plain area.
Climate:
The main climate here is the monsoon climate.
Monsoons bring rains between mid-June and mid-September.
The summers are hot and winters cool.
Topography and population:
The basin has a varied topography.
The environment plays a vital role in the distribution of the population.
The mountain areas with steep slopes have parse population because of inhospitable terrain.
The plain area is densely populated because it is the most suitable for human habitation.
The soil is highly fertile in the plains.
People of the area and their occupation:
Agriculture is taken up as the main occupation where flat land is available to grow crops.
The main crop is paddy.
The staple diet of the people is fish and rice.
Since it requires sufficient water, it is grown in areas where rainfall is high.
The other crops that are grown include wheat, maize, millet and gram. Cash crops such as sugarcane and jute are also grown.
Tea plantations are found in West Bengal and Assam.
Banana plantations are seen in the plains.
In Bihar and Assam, silk is produced by rearing silkworms.
Crops are grown on the terraces of the hills that have gentle slopes.
Flora:
The landforms influence the vegetation of the area.
In the Ganga – Brahmaputra plain tropical deciduous trees grow, along with teak, sal and peepal.
Brahmaputra plain has thick bamboo groves.
The delta is covered with mangrove forests.
Since the climate is cool and the slopes are steep in parts of Uttarakhand, Sikkim and Arunachal Pradesh, coniferous trees like pine, deodar and fir are found.
Fauna:
There is a wide variety of wildlife in this basin.
The common animals are monkeys, tigers, deer and elephants.
The Brahmaputra plain has one-horned rhinoceros.
In the delta area, Bengal tiger, crocodiles and alligator are found.
There is abundant aquatic life too.
Rohu, catla and hilsa are the most popular varieties of fish.
Development of the basin:
The Ganga-Brahmaputra plain has many big towns and cities like Allahabad, Kanpur, Lucknow, Varanasi, Patna and Kolkata.
The river is getting polluted because of the industrial wastes and waste water from these cities.
All the modes of transport are well developed in this area.
The plain area has a good network of roadways, railways and a large number of airports.
The transport, particularly along the rivers is an effective means of waterways transport.
Kolkata is an important port on the River Hoogly.
Tourism is another major activity of this basin. Some of the tourist spots in this area are listed below:
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Location
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Tourist Attractions
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Agra
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Taj Mahal
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Confluence of rivers Ganga and Yamuna
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Allahabad
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Uttar Pradesh and Bihar
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Buddhist Stupas
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Lucknow
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Imambara
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Assam
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Kaziranga, Manas Wildlife Sanctuary
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Arunachal Pradesh
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Distinct tribal culture
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Do You Know?
The population density of Uttarakhand is 159 per sq km, while that of Bihar is 880 per sq km and that of West Bengal is 904 per sq km.
Keywords
River’s Mouth: The place where a river flows into another body of water.
Tributaries: These are the small rivers that join the main river.
River Basin: The main river along with all its tributaries that drain an area forms the river basin. It is also called the catchment area.
