India - Climate, Natural Vegetation, and Wildlife Chapter Notes | Geography for Grade 9 PDF Download

Introduction

Climate of India

• India’s climate varies due to its diverse landforms and relief features.
• Southern India has different temperature, rainfall, and seasonal patterns compared to northern India.
• Coastal areas like Konkan and Malabar experience mild temperatures.
• North-western India faces extreme seasonal changes with sharp contrasts.
• Rainfall varies greatly across regions.
• Mawsynram in Meghalaya gets about 1,080 cm of rain yearly.
• Jaisalmer in Rajasthan receives only 20 cm of rain annually.
• India has a Tropical Monsoon Type climate due to its location in the tropical belt and monsoon winds.
• The Himalayas and Indian Ocean influence India’s unique and varied climate.

Major Seasons of India

Cold Weather Season

• Lasts from December to February.
• Northern India has average temperatures between 10°C and 15°C.
• Caused by slanting sun rays, leading to lower temperatures in the north.

Hot Weather Season

• Starts in March and lasts till May.
• Average temperatures range from 35°C to 45°C.
• Sun rays fall directly on northern regions, causing a rise in temperature.
• April is the hottest month for western and southern India.
• May is the hottest month for northern regions.

Rainy Season

• Known as the south-west monsoon season, lasts from June to September.
• Monsoon arrives via two branches: Bay of Bengal and Arabian Sea.
• Rainfall varies across different parts of the country.

Retreating Monsoon

• Occurs in October and November.
• Winds move back from the mainland to the Bay of Bengal.
• Tamil Nadu, Andhra Pradesh, and parts of southern India receive rainfall during this season.

Factors Affecting the Climate of India

Location and Latitudinal Extent

• India lies between 6°N and 37°6’N latitudes.
• The Tropic of Cancer divides India almost in half.
• Northern India is sub-tropical and temperate.
• Southern India, south of the Tropic of Cancer, is tropical with high temperatures year-round.

Distance from the Sea

• Southern India is surrounded by the Arabian Sea, Indian Ocean, and Bay of Bengal.
• Coastal regions have an equable or maritime climate due to water bodies.
• Interior regions, cut off from the sea, experience an extreme or continental climate.

Himalayas

• The Himalayan and nearby mountain ranges shield India from cold, dry winds of Central Asia in winter.
• They block rain-bearing southwest monsoon winds, preventing them from crossing India’s northern borders.
• Act as a major climatic divide between the Indian subcontinent and Central Asia.

Physiography

• Landforms affect temperature, air pressure, wind direction, wind speed, and rainfall.
• Windward sides of the Western Ghats and Assam get heavy rain from June to September.
• The southern plateau stays dry due to its leeward position along the Western Ghats.

Altitude

• Temperatures are generally high across India.
• Himalayas and other high mountains have cooler temperatures, even in summer, due to high altitude.

Wind Reversal

• Indian climate features a complete wind reversal with seasonal changes.
• In winter, trade winds blow from north-east to south-west, bringing dry, cold conditions.
• In summer, winds reverse, blowing from south-west to north-east, carrying moisture from surrounding water bodies.

Monsoons in India

• The term ‘monsoon’ comes from the Arabic word ‘Mausim,’ meaning season.
• India’s climate is dominated by monsoon winds, blowing from June to September.
• Monsoons involve wind reversal: from land to sea in winter, and from sea to land in summer.
• Most rainfall occurs in summer, while winter remains dry in monsoon-affected areas.

Monsoon of the Bay of Bengal Branch

• Affects Bangladesh, West Bengal, and Odisha.
• Winds reach Meghalaya, getting trapped in tunnel-shaped mountains.
• Mawsynram and Cherrapunji receive the world’s highest rainfall due to this entrapment.

Monsoon of the Arabian Sea Branch

• Winds travel over the Arabian Sea, hitting the western coast and northern plains.
• Rainfall is less compared to Assam.
• Lasts from June to September.

Winter Monsoon

• India’s interior cools more than surrounding oceans in winter.
• Winds reverse, blowing from high-pressure land to low-pressure oceans, creating the north-east monsoon.

Features of Monsoons in India

• Orographic rainfall: Mountain ranges block moisture-bearing winds, causing heavy rain on windward sides and little on leeward sides.
• Rainfall is unpredictable, varying in amount and timing, leading to floods or droughts.
• Most rainfall happens in summer due to southwest monsoon winds.
• North-east winter monsoon brings limited rainfall.
• Rainfall distribution is uneven: some areas get over 200 cm, facing floods, while others get less than 50 cm, facing semi-desert conditions.
• Bay of Bengal, Arabian Sea, and Indian Ocean cause most rainfall, but varied temperatures lead to uneven distribution.

Retreating Monsoon and Its Effect

• Winter season brings high pressure over north-western India.
• Cold, dry winds blow from this region to southern low-pressure areas.
• Winds pass over water bodies around Peninsular India but remain dry, causing cold, dry weather.
• Northeast monsoon winds pick up moisture over the Bay of Bengal, bringing rain to the Coromandel Coast in eastern Tamil Nadu.

Sociocultural Impact of Monsoon on India

• Climatic variations are unified by monsoon winds and the Himalayas’ role.
• Hot, wet, and cold seasons influence lifestyles and economic activities.
• Farmers begin ploughing, sowing, and transplanting with or before the monsoon.
• Winter sees wheat as a major rabi crop in cool, irrigated areas.
• Barley, gram, and oil seeds are common in unirrigated northern and central India.
• People wear cotton clothes in summer and woollen clothes in winter, especially in north and central India.
• Rain occurs for a few months, with dry periods the rest of the year.
• Rainy season is celebrated, with festivals tied to harvesting and cropping.
• Traditional farming is rain-fed subsistence in most villages.
• Different regions grow different crops due to seasonal and regional weather variations.

Natural Vegetation of India

Natural vegetation means a group of plants that grow naturally in an area without human interference over a long time. India is lucky to have a diverse and rich variety of such natural vegetation. The country is home to a vast range of plant and animal life.
India’s natural vegetation can be grouped into eight major floristic regions: the Western Himalayas, Eastern Himalayas, Assam, the Indus Plain, the Ganga Plain, the Deccan region, the Malabar Coast, and the Andaman Islands.

Therefore, natural vegetation in India is generally divided into the following categories: 

• Tropical Evergreen Rainforest
• Deciduous Vegetation or Monsoon Type Forests 
• Semi-desert and Desert Vegetation
• Tidal or Mangrove Forests 
• Mountain Forests

Tropical Evergreen Rainforests

• Thrive in areas with about 200 cm of rainfall, surviving short dry spells.
• Trees grow tall, up to 60 meters or more.
• Found on Western Ghats slopes, north-eastern regions (Arunachal Pradesh, Meghalaya, Assam, Nagaland), Tarai areas of Himalayas, and Andaman Islands.
• Trees grow densely, with no set leaf-shedding period.
• Key trees include sishu, chaplash, rosewood, mahogany, bamboo, garjan, and eucalyptus.
• Common animals: elephant, okapi, jaguar, gibbon, hippopotamus, armadillo, monkey, and lemur.

Deciduous or Monsoon Type of Forests

• Grow in areas with 100-200 cm of rainfall.
• Trees shed leaves for 6-8 weeks during dry summer and winter.
• Found along Himalayan foothills, eastern Western Ghats, wet Deccan plateau, plains of Bihar and Uttar Pradesh, and in Odisha, Chhattisgarh, and Jharkhand.
• Main trees: teak, sal, peepal, neem, sandalwood, deodar, blue gum, ebony, shisam, jackfruit, mahua, pal ash, arjun, khair, and bamboo.
• Teak is the dominant species.
• Animals include lion, tiger, pig, deer, monkey, and nilgai.

Semi-desert and Desert Vegetation

• Found in areas with less than 50 cm of rainfall.
• Includes thorny bushes, acacia, babul, and sand-binding grasses.
• Indian wild date is common in these deserts.
• Plants have long roots and thick, fleshy stems to store water for droughts.
• Located in Rajasthan and dry parts of Gujarat, Punjab, and Deccan Plateau.
• Animals: camel, fox, lizard, snake, and other reptiles.
• Thar Desert hosts chinkara, Great Indian Bustard, Indian wild ass, 23 lizard species, and 25 snake species.

Tidal or Mangrove Forests

• Grow along coasts and delta edges, like those of Ganga, Mahanadi, Godavari, Krishna, and Kaveri.
• Called Sundarbans in West Bengal.
• Sundari is a key tree in these forests.
• Other trees: hogla, garan, gewa, golpata, pasur, palm, and coconut.
• Trees have breathing roots to survive in oxygen-poor mangrove mud.
• Provide timber and firewood.
• Sundarbans host royal Bengal tiger, saltwater crocodile, horseshoe crab, olive ridley turtle, and Ganga dolphin.

Mountain Forests

• Also called Alpine or Montane forests.
• Vary along mountain slopes.
• Evergreen trees (sal, teak, bamboo, cane) grow up to 1,500 meters in Himalayan foothills.
• Temperate conifer trees (pine, fir, oak, maple, deodar, laurel, spruce, cedar) grow between 1,500 and 3,500 meters.
• Rhododendrons and junipers grow at higher Himalayan altitudes.
• Alpine grasslands appear beyond these belts, up to the snowfield.
• Animals: snow leopard, panda, yak, tahr, musk deer, and chiru.

Conservation of Forests

• First National Forest Policy (NFP) was set in 1894 by the British.
• Revised in 1952 after independence, targeting 33% forest cover.
• Current policy aims for 60% forest cover in hills and 20% in plains.
• Steps to conserve forests:
• Stop indiscriminate deforestation.
• Avoid wasting timber and firewood.
• Increase forest area through afforestation.
• Use alternative energy sources like biogas instead of firewood.
• Prevent forest fires.
• Control pests and diseases of forest trees chemically and biologically.
• Discourage cattle grazing in forests.
• Reforest deforested areas.
• Undertake large afforestation in areas unfit for agriculture.
• Adopt improved and selective cutting for forest management.

Afforestation Programmes of the Government of India

Social Forestry Programme (1976)

• Trees grown on public and common land for rural community benefit.
• Provide firewood, fodder, and fruits.
• Aims to reduce pressure on existing forests.

Agro-forestry Programme

• Revives ancient practice of using land for farming, forestry, and animal husbandry.

Reserve Forests

• Trees grown in ecologically fragile areas.
• Felling of trees and cattle grazing are banned.
• Van Mahotsava, a tree plantation day, held in February and July since 1950 to promote forest conservation.
• International agencies like World Bank, USAID, CIDA, and SIDA support afforestation.
• Central Arid Zone Research Institute in Jodhpur works to check Rajasthan desert spread.

Wildlife in India

• India hosts over 89,000 animal species and 1,200 bird species.
• Has 5-8% of the world’s amphibians, reptiles, and mammals.
• Animals include one-horned rhinoceros, wild ass, camel, Indian bison, blue bull, Barasingha, deer, and monkeys.
• India is unique in having both tigers and lions.
• Gir Forest in Gujarat is the natural home of lions.
• Tigers live in Sundarbans (West Bengal), Madhya Pradesh forests, and Himalayan region.
• High-altitude areas host yak, Tibetan antelope, bharal, and Kiang.
• Elephants live in hot, wet forests of Assam, Karnataka, and Kerala.

Threats to Indian Wildlife

• Wildlife sanctuaries are overcrowded, reducing their capacity.
• Increased ecotourism and adventure tourism raise tourist footfall in national parks.
• Vehicle pollution and wildlife road fatalities harm natural habitats.
• Wildfires from campfires kill animals and destroy habitats.
• Water pollution from chemicals and toxic effluents threatens animals and birds.
• Poaching remains a threat, even with sanctuaries and parks in place.

Steps Taken by the Government for Preservation of Flora and Fauna

• India has 18 biosphere reserves, including Sundarbans (West Bengal), Nanda Devi (Uttarakhand), Gulf of Mannar (Tamil Nadu), and Nilgiris (Kerala, Karnataka, Tamil Nadu).
• Other reserves: Nokrek, Great Nicobar, Manas, Simlipal, Dihang-Dibang, Dibru Saikhowa, Agasthyamalai, Kanchenjunga, Pachmari, Panna, and Achanakmar-Amarkantak.
• Projects like Project Tiger, Project Rhino, and Project Great Indian Bustard aim to revive endangered species.
• 89 national parks, 49 wildlife sanctuaries, and zoological gardens established for conservation.

National Parks

• Areas set aside to protect rare fauna, flora, geological formations, and scenic environments.
• Hunting, killing, or capturing fauna is banned.
• Depriving animals of habitat or destroying flora is prohibited.
• Weapons are not allowed inside parks.
• Only activities for wildlife protection and management, handled by park authorities, are allowed.
• Grazing of livestock is strictly banned.
• Boundary changes require state legislature resolution.

Some Important National Parks

Jim Corbett National Park

• Oldest national park in India, located in Nainital, Uttarakhand.
• Set up to protect the endangered Bengal tiger.
• Hosts 488 plant species and diverse fauna.
• Tourist activity and other issues challenge its ecological balance.
• Named after Jim Corbett, key in its establishment in the 1930s.

Ranthambore National Park

• Located in Sawai Madhopur, Rajasthan, one of the largest in northern India.
• Became a national park in 1980.
• Adjacent forests declared Sawai Man Singh and Keladevi Sanctuaries in 1984.
• Tiger reserve expanded in 1991 to include these sanctuaries.
• Known for Bengal tigers, ideal for seeing them in their natural jungle habitat.

Kaziranga National Park

• A World Heritage Site in Assam, on the Brahmaputra banks.
• Ideal habitat for the rare one-horned rhinoceros.
• A paradise for bird watchers, hosting many migratory birds in winter.

Sundarbans

• World’s largest estuarine forest and delta, in lower Gangetic West Bengal.
• Boats glide through creeks and rivulets bordered by mangrove forests for tourism.

Gir Forest National Park

• Gir Forest National Park is the home of the Asiatic lions and is located in Gujarat.
• The thick and undisturbed forests make it a perfect sanctuary for wild animals such as the spotted deer, sambar, nilgai, and antelope.