MAJOR LANDFORMS

We all know that one – fourth of the earth’s surface is covered by land. The portion which forms land on earth’s surface is not the same everywhere. At some places the land may be too high, at some places very low, some areas would be lush green and certain areas are dry and barren. Our planet earth is a beautiful collaboration of various physical features.

These different physical features are called the various landforms on the surface of the earth. These are geographical features that control the ecosystem, climate, weather and the essence of life on earth. In simple terms, we say that any shape on the earth’s surface is known as a landform. The various landforms that we have, came into existence due to natural processes such as erosion, wind, rain, weather conditions such as ice, frost and chemical actions. Natural events and disasters such as earthquakes (the tectonic plates) and eruption of volcanoes created the various shapes of the land that we see.

The different major landforms are mountains, hills, valleys, plateaus, plains and deserts.

Facts about Mountains

·         A mountain is the highest landform on the surface of the earth. It is usually found to be conical in shape with steep sides and a pointed tip called a peak.

·         As compared to their surroundings, mountains are high points on the surface of the earth.

·         Mountain range is a series of mountains.

·         Mountains could be steep and snow covered or they could be gently sloping having rounded tops.

·         The highest mountain range in the world is the Himalayas. Some mountains are found under the sea and could be taller than the Mount Everest, which is the highest mountain peak in the world.

4 Types of Mountains

Ø  Volcanic Mountains

Ø  Fold Mountains

Ø  Block Mountains

Ø  Residual Mountains

·         Mountains could be formed when molten rocks from deep within the earth rise to the surface, pouring out in the form of lava from volcanoes.

·         Sometimes the tectonic plates on the earth’s crust move towards each other, the sediments deep below the earth’s surface are squeezed up to form mountain ranges.

·         There are many mountains that remain covered with snow throughout the year. These mountains are very cold and hence there is not much vegetation or life found in these hills. Trees like pine and conifer are found in the lower ranges or foothills.

·         Animals that have a thick fur coat can survive the extreme cold in the high mountain regions. The yak, the mountain puma, snow leopard or the male goat called the ibex are some of the animals found in the mountain areas.

·         Houses in the mountains have sloping roofs to enable the snow slide off easily. The houses are made of wood so that they remain warm. People usually work in small industrial units, farming and animal rearing form their main occupations.

·         Even besides harsh conditions, mountains are very useful to us as they act as shields for the country blocking the cold winds and also protect us from invading enemies.

·         Trees provide us with commercial and medicinal value.

·         Melting snow from the snowcapped mountains fills the rivers and they are a source of water.

·         They make beautiful tourist destinations.

Facts about Hills

·         Hills are lower than mountains but are higher than their surrounding areas.

·         Hills are lower in height than mountains, but they are higher than the surrounding areas. A number of hills together form a ‘range of hills’. Hills are usually covered with grass.

·         The climate in the hills is more pleasant than the climate in high snow covered mountains. It is usually neither too hot nor too cold. They make perfect tourist destinations.

·         The vegetation is thick, beautiful fruit orchards are found in the hills and it is good for crop cultivation like tea and coffee.

Facts about Valleys

·         Valleys are the low-lying areas between two mountains or hills.

·         When rivers flow down the mountainsides and hillsides, it wears off the rocks and soil. Over a period of time, the water carves out v- shaped grooves. These grooves get deeper and wider, finally forming low land areas called valleys.

·         Valleys formed by glaciers are U- shaped valleys.

·         Valleys formed due to the effect of erosion are V – shaped valleys.

·         The valleys formed (that is V shaped or U shaped), depend upon the rate at which deepening and widening takes place.

·         Narrow valleys are called canyons.

·         The climate in the valleys is pleasant and favourable for living, hence many civilizations in ancient times were found in valleys where there were rivers flowing making water available for the people.

·         For example The Indus Valley Civilization that came up near the River Indus.

·         Due to ample water that is provided by the rivers and fertile soil, the vegetation is thick and valleys look green and beautiful.

·         They make great tourist destinations as well.

·         In Young Mountain areas the valleys found are steep sided.

Facts about Plateaus

·         A plateau is a flat topped highland with steep sides. Since it looks like a table, it is also called a tableland. They are basically areas of high flat land.

·         Plateaus are usually surrounded by steep rock faces called cliffs.

·         Some plateaus like the Plateau of Tibet lies between mountain ranges.

·         Plateaus are usually good for growing certain crops.

·         Plateaus are formed when magma pushes up towards the surface of the earth’s crust. This magma does not break through but it raises a portion of the crust up creating a plateau.

·         There are certain kinds of plateaus like the butte and the mesa. These are special kinds of plateaus.

Facts about Plains

·         Plains as you all are familiar with are areas of flat land.

·         The plains usually meet the oceans or seas, these are called coastal plains.

·         In India, we have the Eastern Coastal Plains and the Western Coastal Plains.

·         Some plains are formed by the action of rivers, these are called river plains.

·         In India the Northern Gangetic Plain is a river plain.

·         River plains are very fertile and good for growing crops.

·         You will find most big cities are located in plains. This is because it is easier to build houses, buildings, roads and other structures in the plains. Hence they are heavily populated.

Facts about Islands

·         An island is a piece of land surrounded by water on all sides.

·         The continent of Australia is an island.

·         Islands are formed due to volcanic activity or due to hot spots in the lithosphere.

·         Coral islands are formed when the skeletal material of the corals piles up over a long period of time. These look beautiful.

·         A large group of islands close to each other together form an archipelago. The Lakshadweep islands are an example of an archipelago. The largest archipelago in the world is Indonesia.

Deserts : Facts and Types

·         Deserts are large, dry and hot areas of land which receive little or no rainfall throughout the year. The vegetation is scanty due to the shortage of water. Deserts are covered with sand.

·         Sand dunes are formed in deserts. Sand dunes are huge hills of sand formed by the winds.

·         Deserts have extreme weather conditions, days could be very hot and nights very cold. This is because the sand absorbs heat fast during the day and gives off heat quickly at night.

·         The main vegetation found in the deserts are the cacti and the baobab trees.

·         The baobab tree can store nearly up to 1000 litres of water in its trunk which enables it to survive the harsh conditions.

·         There are two types of deserts – Hot Deserts and Cold Deserts.

Hot Deserts

·         As the name suggests, hot deserts are vast areas of land that are covered with sand and dust. These areas receive little or no rainfall and are very dry.

·         The animals found in the hot deserts are camels, snakes, lizards and rats.

·         Thar Desert in India is a hot desert.

Cold Deserts

·         The cold deserts are large areas of land covered with snow. These deserts receive little or no rainfall. They receive snowfall during the winters. Animals such as penguins, whales and fur seals survive in the cold deserts.

·         The Antarctica is the world’s biggest cold desert.

·         Life in these cold deserts is impossible.

·         There are some rocky deserts like the Gobi desert in Asia.

·         Some other Landforms

·         Peninsula

·         A peninsula is a piece of land that is surrounded by water from three sides. For example the southern part of India is a peninsula as it is surrounded by the Arabian sea, Bay of Bengal and the Indian ocean and is joined to land on the fourth side.