Chapter 7 — Human Environment Interactions

Chapter 7 of NCERT Class 7 Geography 'Our Environment' examines human-environment interactions in two major basins — the Amazon Basin in equatorial South America and the Ganga-Brahmaputra Basin in the subtropical Indian subcontinent — showing how climate and landforms shape livelihoods, food, and shelter.

The chapter contrasts two river basins. The Amazon Basin lies between 10°N and 10°S in South America; its hot, wet equatorial climate supports dense rainforests rich in wildlife — toucans, piranhas, anacondas, and tapirs. People practise slash-and-burn farming, grow manioc as their staple, and live in thatched huts or large Maloca houses. The Trans-Amazon Highway (built 1970) opened the forest to development, displacing indigenous communities and accelerating deforestation. The Ganga-Brahmaputra Basin spans 10°N–30°N in the Indian subcontinent, with fertile plains suited to paddy, wheat, sugarcane, and jute. It harbours the one-horned rhinoceros, Bengal tiger, and the blind dolphin Susu. Major cities such as Varanasi, Patna, and Kolkata line the Ganga; tourism draws visitors to landmarks including the Taj Mahal and Kaziranga.

1. 01The Amazon Basin is the largest river basin in the world, in the equatorial region (10°N–10°S), draining parts of Brazil, Peru, Bolivia, Ecuador, Colombia, and a small part of Venezuela.
2. 02Amazon's hot, wet climate produces dense rainforests where the leaf-and-branch canopy blocks sunlight from the ground; notable wildlife includes toucans, macaws, piranha, anacondas, tapirs, and sloth.
3. 03Amazon people practise slash-and-burn agriculture; their staple is manioc (cassava); homes range from thatched beehive-shaped huts to large Maloca houses with steeply slanting roofs.
4. 04The Trans-Amazon Highway (1970) made the rainforest accessible, displaced indigenous communities, and accelerated deforestation; when forest cover is lost, topsoil is washed away by rain.
5. 05The Ganga-Brahmaputra Basin lies in the subtropical region (10°N–30°N); its fertile plains support paddy (main crop), wheat, sugarcane, jute, tea (West Bengal and Assam), and silk (Bihar and Assam).
6. 06Basin vegetation ranges from tropical deciduous trees (teak, sal, peepal) and Sundarbans mangroves in the delta to coniferous forests (pine, deodar, fir) in the Himalayan foothills of Uttarakhand, Sikkim, and Arunachal Pradesh.
7. 07Unique wildlife includes the one-horned rhinoceros in the Brahmaputra plain, Bengal tiger and crocodiles in the delta, and the blind dolphin Susu — whose presence indicates river health — in the Ganga and Brahmaputra.
8. 08Six cities with populations above ten lakhs lie along the Ganga — Allahabad, Kanpur, Varanasi, Lucknow, Patna, and Kolkata; industrial and urban wastewater discharged into the rivers causes serious pollution.