Tropical And Subtropical Regions

Amazon basin Ganga Brahmaputra basin

Tropical region • The tropics is a region of the earth surrounding the equator. It is limited

in latitude by the Tropic of Cancer in the northern hemisphere at 23°26′14.1″ (or 23.43726°) N and the Tropic of Capricorn in the southern hemisphere at 23°26′14.1″ (or 23.43726°) S; these latitudes correspond to the axial tilt of the Earth. The tropics are also referred to as the tropical zone and the torrid zone . The tropics include all the areas on the Earth where the Sun reaches a subsolar point, a point directly overhead at least once during the solar year.

• The tropics are distinguished from the other climatic and biomatic regions of Earth, the middle latitudes and the polar regions on either side of the equatorial zone.

Subtropical region• The subtropics are geographic and climate zones located roughly

between the tropic circle of latitude the Tropic of Cancer and Tropic of Capricorn and the 38th parallel in each hemisphere. Subtropical climate regimes can exist at high elevations within the tropics, such as across the Mexican Plateau and in Vietnam and Taiwan. Also places like Hong Kong, although inside the tropics, have a subtropical climate due to the influence of cold Siberian air masses. Six climate classifications utilize the term to help define the various temperature and precipitation regimes for the planet Earth. Eight months of the year within the subtropics have an average temperature at or above 10 °C (50.0 °F), with their coldest month averaging between 2 and 13 °C (35.6 and 55.4 °F).

Basin

• A basin is a depression, or dip, in the Earth’s surface. Basins are shaped like bowls, with sides higher than the bottom. They can be oval or circular in shape, similar to a sink or tub you might have in your own bathroom. Some are filled with water. Others are empty. 

Basins are formed by forces above the ground (like erosion) or below the ground (like earthquakes). They can be created over thousands of years or almost overnight.

The major types of basins are river drainage basins, structural basins, and ocean basins. 

River drainage basin• A river drainage basin is an area drained by a river and all of its tributaries. A river

basin is made up of many different watersheds. 

A watershed is a small version of a river basin. Every stream and tributary has its own watershed, which drains to a larger stream or wetland. These streams, ponds, wetlands, and lakes are part of a river basin. The Mississippi River basin in the U.S., for instance, is made up of six major watersheds: the Missouri, Upper Mississippi, Ohio, Tennessee, Lower Mississippi, and Arkansas-Red-White Rivers. 

Every river is part of a network of watersheds that make up a river system’s entire drainage basin. All the water in the drainage basin flows downhill toward bigger rivers. The Pease River, in northern Texas, is part of the Arkansas-Red-White watershed. It is a tributary of the Red River. The Red River is a major tributary of the Mississippi River, which flows into the Gulf of Mexico.

The Amazon Basin, in northern South America, is the largest in the world. The Amazon River and all of its tributaries drain an area more than 7 million square kilometers (about 3 million square miles). 

Amazon basin - location• The Amazon basin is the part of South America drained by the Amazon

River and its tributaries. The Amazon drainage basin covers an area of about 6,915,000 km2(2,670,000 sq mi), or roughly 40 percent of the South American continent. It is located in the countries of Bolivia, Brazil, Colombia, Ecuador, Guyana, Peru, Suriname and Venezuela.

• Most of the basin is covered by the Amazon Rainforest, also known as Amazonia. With a 5,500,000 km2 (2,100,000 sq mi) area of dense tropical forest, this is the largest rainforest in the world.

Amazon basin –climate

• Hot and wet throughout the year.• Day and night are hot and humid.• High temperature during day and high humidity.• Rainfall almost everyday.

Amazon basin -vegetation

• Dense forest create a “roof” of leaves and branches thus not allowing sunlight to enter the ground.

• The ground thus remain dark and damp and hinders the grow of other plant life.

• Plants which adapt to shade grow here.• Orchids and bromeliads grow as plant parasites.

Amazon basin-wildlife• Birds of paradise are found here.• These birds have large bills for eating and making

loud sounds.• Animals like monkey , sloth are found.• Crocodile ,snakes, python are a part of fauna of this

region.• Piranha are also found in the rivers.

Amazon basin – Food production• People generally grow food in small patches cleared in the forest .they

generally practice slash and burn agriculture.• The staple food is cassava which , like potatoes grow underground.• Common food is grown is tapioca , sweet potato , pineapple.• Coffee ,maize and cocoa are grown as cash crops.• They also hunt ,fish for food, eat queen ants and egg sacs.• The woods from the forest is used to make houses. People also live in

tached houses or even large apartment type houses known as maloca. These houses have a slanting roof.

Amazon basin - people• In earlier times the dense forest were out of reach of people with the

construction of trans highway in 1970 most part of forest were accessible.

• The local population is gradually were been pushed out from the native region and being forced to go in new areas where they can practice their own agriculture methods.

• Development activities were having both positive and negative results on life of people and their habitat construction of roads ,houses and buildings disturb the rain forest; a large areas of rainforest is disappearing year by year due to activities of man.

Ganga-Brahmaputra – Location and Area• The Sub- tropical region is situated between 10

degrees N to 30 degrees N.• Ganga Brahmaputra and their tributaries form the

Ganga Brahmaputra Basin. Tributaries of Ganga- Ghaghara, Son Chambal,Gandak , Kosi and tributaries of Brahmaputra Drain and the Basin. The Himalayas and the Sunder ban Delta are Part of the Basin.

Ganga-Brahmaputra - Climate

• Monsoon climate, Rainfall generally from Mid June to Mid September. Summers are Hot and Winters Cool.

Ganga-Brahmaputra - Vegetation• In Ganga and Brahmaputra plain, tropical deciduous

trees like teak, sal, peepal are found. Bamboo groves grow in Brahmaputra plain.

• Mangrove forest are found in different par of delta regions, especially in Sunderban delta.

• Coniferous trees like pine, deodar, fir are found in hilly regions of Uttaranchal, Arunanchal and Sikkim.

Ganga-Brahmaputra – Wildlife• Animals like monkeys, elephants, tigers, deers are

found in this region. • One horned rhinoceros is found in Brahmaputra plain.• Crocodiles, Alligators, Bengal tigers are also found

here.• Fishes like rohu, catla, and other aquatic life are found

in rivers lakes and Bay of Bengal.

Ganga-Brahmaputra – Food Production• The soil is the most fertile in the flat plains and thus

agriculture is the main occupation.• Main crops grown are wheat, maize and rice. Banana

plantations are found in plains.• Terrace farming is done in hilly and mountainous

areas.• Sugarcane and jute are grown as cash crops.• West Bengal and Assam are famous for tea

cultivations. Silk from silkworm is cultivated in the states of Bihar and Assam.

Ganga-Brahmaputra - People• Human settlements are influenced by the diverse topography and

environmental conditions.• There is a very little settlements in mountainous regions. The major part

of the population lives in the plains which is the most hospitable and suitable for agriculture.

• There are many big cities and towns like Allahabad, Kanpur, Varanasi, Lucknow, Patna and Kolkata. All these places have a population of over 1 million.

• Different modes of transport are developed in this region : Airways, Roadways, Waterways and railways.

• There are several tourist attractions in this regions like Taj Mahal in Agra; Ecutuary point of Ganga-Yamuna and its tributaries in Allahabad; Stupas in UP and Bihar; Wildlife sanctuaries in Assam and Arunachal Pradesh.