Kuttu Proj

Mountains

Definition A mountain is a landform that extends above the surrounding terrain in a limited area. It is ‘higher and steeper than a hill’. Characteristics Mountains are formed by volcanism, erosion, and disturbances or uplift in the earth's crust.The earth’s crust is divided into large pieces called continental plates.When these plates push together they crumple and fold.This creates mountains. The Himalayas, for example, were raised by the compression that accompanied collision of the Indian plate with the Eurasian plate. Mountains usually have steep, sloping sides and sharp or slightly rounded ridges and peaks Most of the world's rivers are fed from mountain sources, and more than half of humanity depends on mountains for water.Some mountains have frozen lakes called glaciers .These are the sources for many rivers.Mountains exist on every continent and even beneath our great oceans. Mountain climate is cold.This is because the Sun heats Earth from the ground up. The Sun's radiation travels through the atmosphere to the ground, where Earth absorbs the heat. Air closest to the Earth's surface is, in general, warmest . Air as high as a mountain is poorly warmed and, therefore, cold.

Valleys

Definition A valley is a hollow or surface depression of the earth bounded by hills or mountains, a natural trough in the earth's surface, that slopes down to a stream, lake or the ocean, formed by water or ice erosion. Characteristics Rivers and streams flowing through valleys drain interior land regions to the ocean. At the bottom of many valleys is fertile soil, which makes excellent farmland..The bottom of a valley is called its floor. The part of the floor along riverbanks is called flood plain. A valley's sides are called valley walls or valley slopes. The form of a valley depends upon the rate at which deepening and widening goes on. V-shaped valleys are caused by forces such as erosion and rivers. Valleys are usually in a U-shaped form. Narrow deep valleys are sometimes called canyons. Erosion by rivers is a main valley-forming process.Steep sided valleys are often found in young mountain areas where the land is still being lifted to create mountains. Steep sided valleys occur because the uplift tends to increase the channel slope, which in turn causes the river to cut more rapidly into its bed.

Plateau

Definition A plateau is a large highland area of fairly level land separated from surrounding land by steep slopes. Characteristics Plateaus are widespread, and together with enclosed basins they cover about 45 percent of the Earth's land surface. Some plateaus, such as the Deccan of India and the Columbia Plateau of the United States, are basaltic and were formed as the result of many lava flows covering hundreds of thousands of square kilometers that built up the land surface. Others are the result of upward folding; still others have been left elevated by the erosion of nearby lands. Plateaus, like all elevated regions, are subject to erosion, which removes great amounts of the upland surface. Low plateaus are often farming regions, while high plateaus are usually suitable for livestock grazing. Many of the world's high plateaus are deserts. The largest and highest plateau in the world is the Tibetan Plateau, called the “the roof of the world”, which is still being formed by the collisions of the Indo-Australian and Eurasian continental plates.The Tibetan plateau covers an area of some 2.5 million square kilometres which is approximately 5000m above sea level. The height of this plateau is such that it is enough to reverse the Hadley convection cycles and drive the monsoons of India to the south.

Rivers

Definition A river is fresh water flowing across the surface of the land, usually to the sea. It flows in a channel. The bottom of the channel is called the bed and the sides of the channel are called the banks. Characteristics Rivers begin at their source in higher ground such as mountains or hills, where rain water or melting snow collects and forms tiny streams called gullies. The great majority of rivers eventually discharge into either the sea or a lake. When one stream meets another and they merge together, the smaller stream is known as a tributary. It takes many tributary streams to form a river. Most settlements were built along major rivers. Rivers provide us with food, energy, recreation, transportation routes, and of course water for irrigation and for drinking. Rivers carry water and nutrients to areas all around the earth. They play a very important part in the water cycle, acting as drainage channels for surface water. Rivers drain nearly 75% of the earth's land surface. River valleys and plains provide fertile soils. Farmers in dry regions irrigate their cropland using water carried by irrigation ditches from nearby rivers. Rivers are an important energy source. During the early industrial era, mills, shops, and factories were built near fast-flowing rivers where water could be used to power machines. Today steep rivers are still used to power hydroelectric plants and their water turbines.

Plains

Definition Plains are broad, nearly level stretches of land that have no great changes in elevation. Plains are generally lower than the land around them; they may be found along a coast or inland. Coastal plains generally rise from sea level until they meet higher landforms such as mountains or plateaus. Inland plains may be found at high altitudes. Characteristics Plant life on plains is controlled by the climate. Thick forests usually thrive on plains in humid climates, grasslands cover fairly dry. Plains are usually well populated because the soil and terrain are good for farming, and roads and railways are easily built between rural towns and cities. A coastal plain is a stretch of lowland along a seacoast which slopes toward the sea. In most cases, such a plain may be an elevated part of the ocean floor. Solid materials are carried off by rivers or waves from other coastal plains; these materials are deposited along the shore extending the coast seaward.The sharp upward slope of the land along the plain's inland edge is called the fall line. Coastal plains generally have a few poor harbors. A flood plain is the floor of a river valley beyond the riverbed. A flood plain is formed of mud, sand, and silt that are left behind when the river overflows its banks. These materials are carried off by the river as it erodes the land upstream. A river in flood conditions can carry a large amount of eroded material, which the overflow waters deposit onto the flood plain.

Coast

Definition The coast is defined as the part of the land adjoining or near the ocean.It is applied to that part of an island or continent that borders an ocean or its saltwater tributaries. Characteristics A large part of the global population inhabits areas near a coast, partly to take advantage of marine resources such as fish, but more importantly to participate in seaborne trade with other nations. Many of the world's major cities that have developed in recent centuries were built on or near good harbours and have large port facilities to take advantage of marine transportation. Coastal areas are major tourist attractions due to the presence of beaches. The Marina beach at Chennai is the second longest beach in the world.Also coastal areas are humid and enjoy frequent rainfall.

Gulf

Definition A gulf is an arm of a sea or ocean partly enclosed by land.It is usually larger than a bay A gulf is another name for a bay. Its shape or location gives some protection from the winds and waves found in the open ocean.

The Gulf of Khambhat (formerly known as the Gulf of Cambay) is an inlet of the Arabian Sea along the west coast of India, in the state of Gujarat. It is about 80 miles in length, and divides the Kathiawar peninsula to the west from the eastern part of Gujarat state on the east. The Narmada and Tapti rivers empty into the Gulf. The Gulf is shallow and abounds in shoals and sandbanks. The Gulf is known for its extreme tides, which vary greatly in height and run into it with amazing speed. At low tide the bottom is left nearly dry for some distance below the town of Khambhat. The Gulf of Khambhat has been an important centre of trade since ancient times; its ports connect central India to the maritime trade routes of the Indian Ocean. Broach, Surat, Khambhat, Bhavnagar, and Daman are historically important seaports. Bharuch has been important since ancient times; Khambhat was the gulf's chief port in the Middle Ages, but after the silting of its harbor, Surat rose to prominence as the most important harbor of the Mughal empire.

Isthmus

Definition An isthmus is a narrow strip of land connecting two larger landmasses. An isthmus has water on two sides. Characteristics Many canals are built on isthmi where it is particularly advantageous to create a shortcut for marine transportation. Of note is the Panama Canal, which connects the Atlantic and Pacific Oceans, and drastically reduces the naval travel time between the east and west coasts of America. Adam's Bridge, also known as Ram Setu meaning "Rama's Bridge", is a chain of limestone shoals, between the islands of Mannar, near northwestern Sri Lanka, and Rameswaram, off the southeastern coast of India. Geological evidence indicates that this bridge acted as former land connection between India and Srilanka. The name Rama's Bridge or Rama Setu (Sanskrit; setu: bridge) was given to this bridge of shoals in Rameshwaram, as Hindu legend identifies it with the bridge built by the Vanara (monkey-men) army of Rama , which he used to reach Lanka and rescue his wife Sita from the Rakshasa king, Ravana, as stated in the Sanskrit epic Ramayana.

Strait

Definition A strait is a narrow, navigable channel of water that connects two larger navigable bodies of water. It most commonly refers to a channel of water that lies between two land masses Characteristics Many straits are economically important. Straits can lie on important shipping routes, and wars have been fought for control of these straits. Numerous artificial channels, called canals, have been constructed to connect two bodies of water over land. Straits are the duals of isthmi. That is, while straits lie between two land masses and connect two larger bodies of water, isthmi lie between two bodies of water and connect two larger land masses. A strait is similar to an inlet although inlets typically pass through island land masses usually from a large body of water such as an ocean to a much smaller body such as a bay while straits pass through much larger land masses and connect much larger bodies of water such as seas and oceans. The Palk Strait is a strait that lies between the Tamil Nadu state of India and the island nation of Sri Lanka. It connects the Bay of Bengal to the northeast with the Gulf of Mannar to the south.

Hills

Definition Hills are elevations of the earth's surface that have distinct summits, but are lower in elevation than mountains. Characteristics Hills may be formed by a buildup of rock debris or sand deposited by glaciers and wind. Hills may be created by faults. Faults are a slight crack in the earth which can cause earthquakes. Hills are formed when these faults go slightly upward. Hills are also formed by deep erosion of areas that were raised by disturbances in the earth's crust. Erosion forms hills by carrying away all of the soil on a mountain, causing a hill to be left behind. Volcanoes form hills when they erupt. During the eruption, volcanic ash is spewed through the air; after the eruption, the lava or molten rock hardens and builds up a thick layer of lava rock. The ash falls on the hardened lava causing a layer of ash to form on the hill. When rain falls, this layer of ash mixes with the rainwater to form black colored water. This black water will freeze causing the lava rock to crack and crumble and eventually erode to form a hill. The term Ghats is often used in reference to the steep mountainous ranges of India; the Western and Eastern Ghats. They are the coastal mountains of India.Ghats are mountains covered by thick forests.

Peaks

Definition A peak, or sometimes in its most extreme form called a glacial horn, is a mountaintop that has been modified by the action of ice during glaciation and frost weathering. Characteristics Ice fields at the head of glaciers develop U- or bowl-shaped basins in the sides of a mountain called cirques (sometimes called corries or cwms). These encroach on each other to produce ridges known as arêtes. The joining together of three or more arêtes forms a peak. A peak has a sharp summit and steep slopes on at least three sides. They are a common shape for mountain tops in well glaciated areas.