Landform Development: A Landform is a feature on the Earth’s surface that is part of the terrain. Mountains, hills, plateaus, and plains are the four major types of landforms. Minor landforms include buttes, canyons, valleys, and basins. Tectonic plate movement under the Earth can create landforms by pushing up mountains and hills. Erosion by water and wind can wear down land and create landforms like valleys and canyons. Both processes happen over a long period of time, sometimes millions of years.
Classification of Landforms
In terms of origin, oceans and continents have certain differences. Generally, the materials which constitute the ocean bottom are harder and heavier than those which constitute the continents. Though the interior of the earth is still in a hot and molten state, it is still undergoing contraction. The contractions could be slow or sudden. Whether slow or sudden, the contractions are continuously altering the form of the earth’s surface. Such changes on the earth’s surface are therefore caused by the actions of internal force. Since the very beginning of the earth, its surface has been continuously subjected to change by the action of river, glaciers, winds, sea waves, earthquakes, etc. Such changes are, therefore, caused by the actions of external force.
Based on the order of Relief Development Landforms can be Classified into:
First order, second order and third order landforms:
Landforms of First Order: By the actions of internal forces anticlines and synclines were formed and in course of time these have been identified as continents and oceans. That is why, they are called as Landforms of First Order or Primary landforms. The continental landforms consist of Americas, Eurasia, Africa, Australia and Antarctica. The total area is nearly 148 million sq km, i.e., 28 per cent of the earth’s surface and average height is 830 metres.
Landforms of Second Order: The plateaus, mountains, plains and extensive deserts of the continents are the example of the landforms of second order on the continents.
Landform of Third Order: Various features which are generally smaller parts of second order landforms or which form on the second order landforms are known as landforms of third order. There are innumerable such landforms over the continents and at the sea floor. Peaks, cols, cirques, gorge, morains, alluvial fans, floodplains, ox-bow lakes, levees, deltas, ocean islands, volcanoes and ridges are some of the many features of third order landforms.
The landforms that are found on the surface of the Earth can also be grouped into 4 of the following categories:
Structural Landforms: These are the result of the Earth’s dynamic forces, such as the solidification of magma or the colossal movements caused by plate tectonics. Imagine colossal shields, majestic fold mountains, expansive rift valleys, and the awe-inspiring presence of volcanoes shaping our landscapes.
Weathering Landforms: Picture the slow, transformative dance of physical, chemical, and biological processes as they decompose rocks through weathering. This gives rise to unique landforms like karst formations, intricate patterned grounds, and the fascinating profiles of different soil layers.
Erosional Landforms: Envision the relentless forces of wind, water, glaciers, and gravity gradually shaping the surface of the Earth. Marvel at the creation of river valleys, the sculpting of glacial valleys, and the dramatic presence of coastal cliffs, all shaped by the erosional powers at play.
Depositional Landforms: Witness the aftermath of these natural processes as they deposit weathered and eroded materials, occasionally transforming into sedimentary rocks through pressure, heat, and chemical processes. Think of the serene beauty of beaches, the intricate deltas, the fertile flood plains, and the intriguing glacial moraines.
It’s important to note that many landforms bear the marks of multiple processes, earning them the title of “polygenetic.” Furthermore, the dynamic nature of Earth means that processes can change over time, leading to several cycles of development in a single landscape—an evolution known as “polycyclic.”
Read Also: Landforms on The Earth
