Human Environment Interactions — Class 7 Social Science

Human life is closely related to the environment. The natural environment shapes how people live, what they eat, what they wear, and how they earn their livelihood. At the same time, human activities also modify the environment.

Key Environmental Factors Influencing Human Life:

• Climate: Temperature and rainfall determine the type of crops grown and clothing worn
• Landforms: Plains are suitable for farming; mountains influence settlement patterns
• Vegetation: Forests provide food, fuel, timber, and medicines
• Wildlife: Animals provide food, leather, and are part of the ecosystem
• Water Bodies: Rivers and lakes support agriculture, transport, and drinking water supply

In this chapter, we compare two major river basins:

• Amazon Basin (South America) - Tropical region near the Equator
• Ganga-Brahmaputra Basin (Indian subcontinent) - Subtropical region

The Amazon Basin is located in South America, near the Equator. It is the largest river basin in the world, drained by the Amazon River and its tributaries.

Climate of the Amazon Basin:

• Hot and wet climate throughout the year
• Heavy rainfall and high humidity
• Temperature remains high due to proximity to the Equator
• No distinct dry season; rain occurs almost daily

Rainforests of the Amazon Basin:

• Dense tropical rainforests grow here due to heavy rainfall and high temperatures
• Tall trees form a thick canopy that prevents sunlight from reaching the ground
• The forest floor remains dark and damp
• Orchids and bromeliads are common plants that grow on tree trunks
• The rainforest is often called the "lungs of the Earth" because it produces a large amount of oxygen

Wildlife of the Amazon Rainforest:

• The rainforest has rich biodiversity
• Birds: Toucans, hummingbirds
• Mammals: Monkeys, sloths, tapirs
• Reptiles: Snakes, crocodiles
• Fish: Piranha (flesh-eating fish)

The people of the Amazon Basin live close to nature. Their lifestyle is directly influenced by the dense rainforest and the river system.

Lifestyle of the People:

• Men hunt and fish for food
• Women grow crops in small clearings
• They practice slash and burn agriculture (also called shifting cultivation)
• In this method, a patch of forest is cleared by cutting and burning trees, crops are grown for a few years, and then the patch is abandoned for a new one

Agriculture in the Amazon Basin:

• Staple food: Manioc (also called cassava) - a root vegetable
• Other crops: Tapioca, pineapple, and sweet potato
• Cash crops: Coffee and cocoa are grown for commercial purposes

Houses:

• People live in thatched houses with sloping roofs to drain rainwater
• Large communal houses called Maloca are shared by several families
• Malocas are built using wood, palm leaves, and other natural materials from the forest

Changes in the Amazon Basin:

• The construction of the Trans-Amazon Highway opened up the interior of the rainforest
• This has led to large-scale deforestation
• Soil erosion has increased as tree cover is removed
• Indigenous people have been displaced from their traditional lands
• Loss of biodiversity and destruction of habitats are major concerns

The Ganga-Brahmaputra Basin lies in the Indian subcontinent in the subtropical region. It is formed by the rivers Ganga and Brahmaputra and their tributaries.

Climate of the Ganga-Brahmaputra Basin:

• The region experiences monsoon climate
• Hot summers and cool winters
• Most of the rainfall occurs during the monsoon season (June to September)
• Distinct seasons unlike the Amazon Basin which is hot and wet all year

Agriculture:

• Paddy (rice) is the main crop
• Other food crops: Wheat, maize, millets, and gram
• Important cash crops: Sugarcane and jute
• The fertile alluvial soil and abundant water make this region one of the most productive agricultural areas

Vegetation:

• Tropical deciduous forests grow in the plains
• Bamboo is commonly found in the Brahmaputra plains
• Mangroves grow in the delta regions (e.g., Sundarbans)
• Deciduous trees shed their leaves in the dry season to conserve water

Wildlife:

• Elephants, tigers, deer are found in the forests
• One-horned rhinoceros is found in the Brahmaputra plains (Kaziranga National Park)
• Bengal tiger is found in the Sundarbans delta region
• Rivers support rich aquatic life including various fish species

Transport and Cities in the Ganga-Brahmaputra Basin:

• The basin has well-developed transport networks
• Roadways: National highways connect major cities
• Railways: Extensive railway network for both passenger and freight transport
• Waterways: Rivers are used for inland water transport
• Airways: Major cities have airports connecting to the rest of India and the world

Major Cities:

• Prayagraj (Allahabad): Located at the confluence of Ganga and Yamuna
• Kanpur: Major industrial city
• Varanasi: One of the oldest cities in the world; important religious centre
• Patna: Capital of Bihar; located on the banks of the Ganga
• Kolkata: Located near the mouth of the Ganga; major port city

Pollution Problems:

• Industrial waste is dumped into rivers, polluting the water
• Sewage from cities flows into rivers untreated
• Agricultural runoff containing pesticides and fertilizers contaminates water
• Pollution threatens aquatic life and affects people who depend on rivers for drinking water

Conservation Programmes:

• Namami Gange: Government programme to clean and rejuvenate the Ganga river by reducing pollution, improving sewage treatment, and conserving biodiversity
• Swachh Bharat Mission: Nationwide programme for cleanliness and sanitation that also helps reduce river pollution
• These programmes aim to achieve sustainable development by balancing economic growth with environmental protection