Landforms and LifeClass 6 Social Science Notes

Landforms and Life

Introduction

Our planet, Earth, is home to a vast variety of physical features, which we call landforms. Humans, like many other mammals, primarily live on land. As you travel from one place to another, you'll notice that the appearance of the land changes significantly. For example, a journey from the Chhota Nagpur region in Jharkhand to Prayagraj in Uttar Pradesh and then to Almora in Uttarakhand would reveal very different landscapes. These changes are due to the presence of different landforms.

Landforms are physical features found on the Earth's surface. They are shaped over millions of years and have a deep connection with the environment and the life that inhabits them. Broadly, landforms are classified into three main categories: mountains, plateaus, and plains. Each of these landforms has its own unique climate, and they support a diverse range of plants (flora) and animals (fauna). While humans have successfully adapted to live in all types of landforms, the density of population varies greatly across them.

Mountains

Mountains are prominent landforms that rise significantly higher than the surrounding landscape. They typically have a wide base, steep slopes, and a narrow peak known as a summit.

• Snow and Rivers: Depending on their height, some mountains are covered in snow. At lower altitudes, this snow melts during the summer, providing water that feeds rivers. At very high altitudes, the snow might never melt, leaving the mountain permanently snowcapped.
• Hills: Other elevated areas that are lower in height, have less steep slopes, and feature rounded tops are called hills.
• Precipitation: When water from the atmosphere reaches the ground in any form, it's called precipitation. Common forms include rain, snow, and hail. In colder, higher altitude regions like the Himalayas, precipitation often falls as snow, covering the landscape in a white blanket. Snow and hailstones are essentially solid forms of water precipitation.

Major Mountain Ranges and Peaks

Most of the world's mountains are organized into long chains called mountain ranges, which can stretch for thousands of kilometres.

• Himalayas: Found in Asia, home to some of the world's highest peaks.
• Alps: Located in Europe.
• Andes: Stretching across South America.

Some notable mountains and their locations include:

• Mount Everest: The highest peak in the world (8,849 m), situated between Tibet (China) and Nepal. Tibetans call it 'Chomolungma' (Mother Goddess of the World), and Nepalis call it 'Sagarmatha' (Goddess of the Sky).
• Kanchenjunga: Another high peak in the Himalayan range, located between Nepal and the Indian state of Sikkim.
• Mount Aconcagua: The highest peak of the Andes, in South America.
• Mount Kilimanjaro: An isolated mountain in eastern Africa, meaning it's not part of a larger range.
• Mont Blanc: The highest mountain in the Alps, located in Western Europe.
• Anamudi (or 'Anai Peak'): The highest mountain in south India, located in Kerala.

Age and Formation of Mountains

Mountains vary in their age and how they were formed:

• Young Mountains: Mountains with tall and sharp peaks, such as the Himalayas, are considered relatively 'young'. This means they formed more recently in Earth's history, though this still refers to millions of years ago. These mountains, like the Himalayas, are still growing in height due to processes of upliftment and erosion.
• Old Mountains: Shorter and more rounded mountains and hills, such as the Aravalli Range in India, are much older. Their rounded appearance is a result of extensive erosion over vast periods of time.

Mountain Environment

Mountain slopes are often covered with distinct types of vegetation:

• Montane Forest: This type of forest is common on mountain slopes, featuring conifer trees like pines, firs, spruce, and deodar. These trees are typically tall, cone-shaped, and have thin, pointed leaves.
• Higher Altitudes: As altitude increases, trees become sparse, giving way to grasses, mosses (small green plants without flowers or true roots), and lichens (plant-like organisms that cling to rocks or trees).
• Fauna: Deep forests, flowing rivers, lakes, grasslands, and caves in mountains provide diverse habitats for animals such as the golden eagle, peregrine falcon, Canadian lynx, snow leopard, ibex, Himalayan tahr, mountain hare, yak, grey fox, and black bear.
• Rivers: The Ganga (also known as 'Ganges' in English), India's largest river, originates in the Himalayas. It is nearly 2,500 km long and has many tributaries (other rivers joining it), such as the Yamuna and Ghagara, which also originate in the Himalayas. Other tributaries, like the Son or Sone, originate from the Vindhya Range to the south of the Ganga plain.

Life in the Mountains

Life in the mountains presents both unique opportunities and significant challenges.

• Terrain: The mountain terrain (a piece of land from the view of its physical features) is typically rugged, rough, and characterized by steep slopes.
• Farming: Regular farming is difficult due to the steep slopes and is mostly limited to valleys. On the slopes, people practice terrace farming, where steps are cut into the hillside to create flat areas for cultivation. In many mountainous regions, herding livestock is a more common occupation than agriculture.
• Tourism: The crisp mountain air and beautiful scenery make mountains popular tourist destinations, which is a significant source of income for local communities. Activities like skiing, hiking, mountaineering, and paragliding attract visitors. Mountains have also been important sites for pilgrimages to holy places for centuries.
• Challenges: An excessive influx of tourists can put pressure on the fragile mountain environment, making it difficult to maintain a balance. Natural challenges include:
  • Flash flood: A sudden local flood, often caused by a cloudburst (a sudden violent rainstorm).
  • Landslide: The sudden collapse of a mass of earth or rock from a mountainside.
  • Avalanche: The sudden fall of snow, ice, or rocks from a mountainside, often triggered by melting snow.
• Human Resilience: Despite these difficulties, people choose to live in mountains, demonstrating remarkable adaptability. Examples of human achievement include Bachendri Pal, the first Indian woman to climb Mount Everest in 1984, and Arunima Sinha, the first female amputee to climb Mount Everest in 2013, who went on to climb the highest peaks on every continent.
• Cultural Significance: Many traditional communities worldwide consider mountains sacred. Mount Everest is worshipped by Tibetans and Nepalis, and Mount Kailash in Tibet is sacred to followers of Hinduism, Buddhism, Jainism, and Bon. This reverence for mountain summits is common in India and other parts of the world.

Plateaus

A plateau is a landform that rises above the surrounding land and has a relatively flat surface on top. Its sides often feature steep slopes.

• Age and Height: Like mountains, plateaus can be geologically young or old. Their height can vary considerably, from a few hundred metres to several thousand metres.
• Examples:
  • Tibetan Plateau: The world's largest and highest plateau, with an average altitude of 4,500 m. It's often called the 'Roof of the World' and stretches for nearly 2,500 km from east to west.
  • Deccan Plateau: Located in central and south India, it is one of the oldest plateaus globally, formed millions of years ago through volcanic activity.
• Resources: Plateaus are known as 'storehouses of minerals' because they are rich in mineral deposits. Mining is a major activity in these regions, with many of the world's largest mines located on plateaus.
  • [!example] The East African Plateau is famous for gold and diamond mining. In India, the Chhota Nagpur Plateau holds vast reserves of iron, coal, and manganese.
• Environment: The environment of plateaus is very diverse. Many plateaus have rocky soil, which is generally less fertile for farming compared to plains. However, lava plateaus, formed from volcanic activity, are an exception as they often have rich black soil.
• Waterfalls: Plateaus are also home to many stunning waterfalls.
  • [!example] Examples include the Victoria Falls on the Zambezi River in southern Africa, the Hundru Falls on the Subarnarekha River in the Chhota Nagpur Plateau, the Jog Falls on the Sharavati River in the Western Ghats, and the Nohkalikai Falls which plunge 340 metres from the Cherrapunji Plateau in Meghalaya.

Plains

Plains are landforms characterized by an extensive flat or gently undulating surface. They typically lack large hills or deep valleys and are generally not more than 300 metres above sea level (the average level of the ocean's surface).

• Floodplains: A significant type of plain is a floodplain, formed by rivers. Rivers originating in mountain ranges carry particles of rock, sand, and silt, collectively called sediments. These sediments are deposited by the rivers as they flow into the plains, making the soil incredibly fertile.
• Agriculture: Due to their fertile soil, plains are ideal for growing a wide variety of crops, making agriculture a primary economic occupation.
• Flora and Fauna: Plains also support a rich diversity of plant and animal life.

Life in the Plains

Plains have played a crucial role in human civilization and continue to support a large portion of the world's population.

• Civilizations: Thousands of years ago, the first human civilizations emerged around rivers in fertile plains, drawn by the availability of water and productive land.
• Population: Today, a large part of the global population resides in plains. The Ganga plain (often called the 'Gangetic plain') in India is home to about 40 crore people, which is more than one-fourth of India's total population.
• Occupations: Major occupations in plains regions include river fishing and agriculture.
• Crops: A variety of crops are grown, including food crops like rice, wheat, maize, barley, and millets, as well as fibre crops such as cotton, jute, and hemp.
• Challenges:
  • Historically, agriculture in plains was largely rainfed, relying on rainfall. In recent decades, however, there has been a shift towards irrigation, using networks of canals or pumping groundwater to water fields.
  • While irrigation has boosted agricultural production, it has also led to the depletion (decrease) of groundwater, posing a future challenge for agriculture.
  • Other issues affecting plains, especially densely populated ones like the Ganga plains, include high population density and pollution.
• Cultural Value of Rivers: Rivers, whether in mountains or plains, hold immense cultural value worldwide. Many communities consider the source of a river and its confluence (the meeting point of two or more rivers) to be sacred. In India, numerous festivals, ceremonies, and rituals are performed at such holy sites.
• Economic Activities: The gentle slope of plains facilitates easy river navigation, supporting various economic activities. In the past, rivers were extensively used for travel. Even today, certain stretches of rivers, like the Ganga, are used for transportation by boats.

Deserts

While mountains, plateaus, and plains are the three main landforms, the Earth's surface is complex, and other landforms exist. One such landform is the desert.

• Definition: Deserts are vast, dry areas characterized by very little precipitation. They have unique flora and fauna adapted to arid conditions.
• Types:
  • Hot Deserts: Examples include the Sahara Desert in Africa and the Thar Desert in the northwest of the Indian Subcontinent.
  • Cold Deserts: Examples include the Gobi Desert in Asia. Some experts even describe the continent of Antarctica as a desert due to its extremely low precipitation.
• Human Adaptation: Despite the harsh living conditions, humans have adapted to most deserts. In India, communities living in or migrating through the Thar Desert have developed rich cultural traditions, including folk songs and legends, that are deeply connected to their desert environment.
• Resilience: The diverse ways in which humans have made all types of landforms their home is a testament to our remarkable adaptability and resilience (the capacity to meet challenges, adapt to them, or overcome them).

Ancient Tamil Sangam Poetry: Five Tinais

Ancient Tamil Sangam poetry offers a different classification of landscapes called Tinais, which reflect a keen awareness of diverse regions and their characteristics, illustrating the deep connection between humanity and the natural environment. Each Tinai is associated with specific deities, lifestyles, moods, or emotions.

• Kuriñji: Refers to mountainous regions, with hunting and gathering as the main occupation.
• Mullai: Describes grasslands and forests, where cattle rearing was the primary activity.
• Marudam: Represents fertile agricultural plains, focused on farming.
• Neydal: Denotes coastal regions, characterized by fishing and seafaring.
• Pālai: Refers to arid, desert-like regions, associated with journeying and fighting.

Key Takeaways

• Landforms are primarily classified into three main types: mountains, plateaus, and plains. Each has distinct physical characteristics and environments.
• Throughout history, human lives and activities have been significantly influenced by the type of landform they inhabit. These landforms are an integral part of cultures around the world, and Indian culture, in particular, celebrates them in diverse ways.
• Every landform presents its own unique set of challenges and opportunities for the people living there.