Major Landforms of the Earth - Delhi Police Constable PDF Download

Introduction

Landforms are the awe-inspiring shapes that emerge from the Earth's surface over time. They are a result of various natural processes such as weathering, water flow, elevation changes, sinking, and erosion of soil. However, these geological transformations do not occur overnight; they take hundreds and thousands of years to manifest visibly. Let's delve deeper into the processes that contribute to the formation of landforms.

External Process: The Impact of Rain and Wind

External processes are caused by external factors like rain and wind. These processes, namely erosion and deposition, have a significant impact on reshaping the Earth's surface. Erosion involves the movement and transportation of sediments, which are materials like soil and rocks found on the Earth's surface. These sediments are deposited or dropped off in different locations due to natural forces. This constant cycle of erosion and deposition contributes to the creation of diverse landforms.

Internal Process: The Earth's Hidden Forces

Internal processes, on the other hand, occur beneath the Earth's crust, deep within its core. These processes are a result of the intense heat generated in the Earth's core, causing the molten rock in the mantle layer to move. This movement leads to uneven surface changes, including uplifting and sinking of layers. Volcanic eruptions and plate tectonics are examples of internal processes that shape the Earth's surface.

Categorizing Landforms: Mountains, Plateaus, and Plains

Based on their elevation and slope, landforms can be broadly categorized into Mountains, Plateaus, and Plains. Each type possesses its own unique characteristics and plays a crucial role in the Earth's ecosystem and human habitation.

Mountains: Majestic Peaks and Rugged Terrain

Mountains are awe-inspiring landmasses that rise higher and steeper than hills. Generally towering above 2000 feet, mountains create challenging habitats with colder climates as one ascends their heights. These regions often house ice and glaciers, contributing to the source of numerous rivers. Mountainous areas are less suitable for extensive farming due to steep slopes, preserving them as untouched landscapes that harbor endangered species and diverse flora and fauna.

There are three categories of mountains based on their formation:

• Fold Mountains: These mountains are created when tectonic plates collide, leading to folding and upliftment of the Earth's crust. The Himalayas, the Alps, and the Andes are prominent examples, with some being millions of years old.
• Block Mountains: Block mountains form when large areas of rock are displaced vertically due to tectonic stresses. The uplifted blocks are termed as horsts, and the lowered blocks are termed as grabens. The Rhine valley and the Vosges mountain in Europe are examples of block mountains.
• Volcanic Mountains: These mountains are a result of magma rising from the Earth's mantle to the crust, leading to volcanic activity. Kilimanjaro and Mount Fuji are well-known examples of volcanic mountains.

Plateaus: Elevated Flatlands

Plateaus are flat and elevated landforms with one or more sides having steep slopes. They vary in height from a few hundred meters to several thousand meters above the surrounding terrain. Plateaus are often formed through volcanic processes, as lava accumulates and levels the surface. These regions are valuable reserves of minerals like iron ore, manganese, and coal. Notably, plateaus are also the birthplaces of majestic waterfalls, offering breathtaking landscapes for tourism and scenic activities.

Plains: Fertile Lands and Human Habitation

Plains are vast stretches of largely flat land that have been shaped by the flow of rivers and their tributaries. As rivers erode mountains and deposit sediments along their courses and valleys, plains emerge. These fertile regions are ideal for human habitation and agriculture, making them highly populated areas. The Indo-Gangetic plains in India and other similar regions worldwide are vital centers of agricultural activities and human settlements.