Humans Environment Interaction The Tropical.pptx

About Human Environment

1. CH – 6 Humans environment Interaction (the tropical and sub-tropical reigon ) -Amrit Agrawal Vii E

2. The Amazon & ganga- brahmaputra Basin

3. The amazon basin location Located in the continent of South America, the Amazon is the largest river in the world in terms of the volume of water it carries. It rises in the Andes Mountains in Peru and flows eastwards into the Atlantic Ocean. This vast river basin encompasses about 7 ml sq km and covers almost half of Brazil and parts of Bolivia, Peru, Ecuador, Colombia and Venezuela.

4. LAND With more than 1000 tributaries, the Amazon River Basin is the largest in the world. About 20% of the total water carried to the oceans by rivers comes from the Amazon. The materials brought down from the mountains by the Amazon River and its tributaries are deposited, giving rise to the vast alluvial plain.

5. Climate As the Equator passes through this region, the Amazon Basin has a hot and wet climate. There is an absence of seasons and temperatures are uniformly high h throughout the year. The humidity is is generally very high but nights are cooler than days. The rainfall is heavy and occurs throughout the year. It is of the convectional type and occurs almost every day in the afternoon. Hence it is called 4 o'clock rain.

6. Natural Vegetation & Wildlife 1. Natural Vegetation The high temperature and heavy rainfall give rise to dense, luxuriant vegetation in the Amazon Basin. These evergreen rainforests are the largest of their kind in the world and are called selva . The trees are tall with hard wood and broad leaves that form a canopy at the top. This prevents sunlight from penetrating into the forests and the interiors are dark and damp. Mosses and ferns grow on the ground. Climbers like lianas are found along the tall tree trunks . Ebony , mahogany and rosewood are important trees which provide excellent hard timber. The bark of the cinchona tree is used for making quinine which cures malaria. The juice of the chicle tree is used to make chewing gum. The forests also yield a host of other products like rubber, nuts, gums, resins and fibers. However, commercial exploitation of these forests is difficult as a great variety of species grow together in a small area.

7. 2. Wildlife The Amazon Basin is rich in different es of wildlife. A variety of monkeys and sloths are found in the trees. Pumas and jaguars are animals of prey. Tapirs and ancient mammals like anteaters and madillos are found on the ground. reptiles like crocodiles, alligators, turtles, iguanas and different types of snakes including anaconda (the largest snake in the world, around 10 m long) are found in be swamps. The rivers have a rich variety fish, including the fierce flesh-eating piranha. Colourful birds like toucans , humming birds , different types of parrots and a variety of insects are also found in the Amazon Basin.

8. Transportation & Cities The dense forests and swampy grounds e great hindrances in building road and all networks in the Amazon Basin. In the Interiors, waterways are the only mode of transport. There is only one major highway in the region, the Trans Amazonian Highway . There are very few big cities in the Amazon Basin. Manaus, a major rubber-collecting center, and Belem, the chief port of the region, are located in Brazil. Iquitos in Peru is another port . Life in the Amazon Basin has undergone many changes in recent years. With more and more people migrating to this region, the forest cover is gradually getting depleted, giving way to land for grazing and construction. A large number of species of plants and animals are under threat of extinction. The Amazon rainforests are the lungs of our planet. Destruction of these forests through our activities can have disastrous consequences in the future.