Structure And Physiography Class 11 Notes Geography Chapter 2 - CBSE
Chapter : 2
What Are Structure And Physiography ?
- The geological regions based on the physical diversity of India are broadly. The Peninsular Block, The Himalayas and other Peninsular Mountains, Indo-Ganga-Brahmaputra Plain.
- India can be divided into the following physiographic divisions: The Northern and North-eastern Mountains, The Northern Plain, The Peninsular Plateau, The Indian Desert, The Coastal Plains, The Islands.
- The approximate length of the Great Himalayan range, also known as the central axial range, is 2,500 km from
east to west, and its width varies between 160–400 km from north to south. On the basis of relief, alignment of ranges and other geomorphological features, the Himalayas can be divided into the following sub-divisions: Kashmir or North-western Himalayas, Himachal and Uttaranchal Himalayas, Darjeeling and Sikkim Himalayas, Arunachal Himalayas, and Eastern Hills and Mountains.
- The northern plains are formed by the alluvial deposits brought by the rivers; the Indus, the Ganga and the
Brahmaputra. These plains extend approximately 3,200 km from the east to the west. The average width of
these plains varies between 150-300 km. The maximum depth of alluvium deposits varies between 1,000–2,000 m
- Bhabar is a short region at the slope’s break that runs parallel to the Shiwalik foothills for 8–10 km.
- The Tarai belt, which has an approximate width of 10–20 km and is located south of the Bhabar, is where most streams and rivers re-emerge without having a well-defined course, resulting in the marshy and swampy conditions known as the Tarai.
- The irregular triangle known as the Peninsular plateau is rising from the height of 150 m above the river plains
up to an elevation of 600–900 m. Delhi ridge in the northwest (extension of Aravalis), the Rajmahal Hills in the
east, Gir range in the west and the Cardamom Hills in the south constitute the outer extent of the Peninsular
- On the basis of the prominent relief features, the Peninsular plateau can be divided into three broad groups:
The Deccan Plateau, The Central Highlands, and The North-eastern Plateau.
- On the basis of the location and active geomorphological processes, it can be broadly divided into two: The western coastal plains and the eastern coastal plains.
- India has two significant island groups: one in the Arabian Sea and one in the Bay of Bengal. There are approximately 572 islands and islets in the Bay of Bengal island groupings. They are basically located between 6°N and 14°N and 92°E and 94°E. The Ritchie’s archipelago and Labyrinth island are the two main islet groupings.
- Saddle Peak (North Andaman, 738 m), Mount Diavolo (515 m), Mount Koyob (South Andaman, 460 m), and Mount Thullier (Great Nicobar, 642 m) are a few significant mountain peaks in the Andaman and Nicobar islands. These islands are situated between 280 and 480 km off the coast of Kerala. The whole island chain is made up of deposits of coral.