Physiographic divisions

Story hook

In 1965, geologist D.N. Wadia stood on the Karewa Plateau of Kashmir and explained to a group of students why this single landscape contained, in microcosm, three different Indias. To the north, the Greater Himalaya rose in a wall of ice and granite — six kilometres thick, geologically a teenager at 40-50 million years. Below, the Karewa terraces (Pleistocene lake deposits) showed where an ancient lake once filled the Kashmir Valley. And further south, the Pir Panjal range — the Lesser Himalaya — framed the horizon, with its 19th-century hill stations and its walnut and saffron belts. The crux of Wadia's lecture: "India is not one geography. It is six."

That six-fold division — Northern Mountains, Northern Plains, Peninsular Plateau, Indian Desert, Coastal Plains, and Islands — has been the NCERT canon since the 1960s and remains the spine of every Prelims and Mains physiography question. Each division has its own tectonic origin, its own age (the Peninsula is 3,000 million years old; the Indo-Gangetic Plain is 50,000 years young), its own climate signature, and its own strategic significance.

The 2023 Joshimath subsidence in Uttarakhand reminded the nation that the Himalayan division is still tectonically alive. The 2024 Wayanad landslides in Kerala showed the same for the Western Ghats. And the 2024 cyclone Remal that pounded the Sundarbans demonstrated how the Coastal Plains carry their own vulnerability. This file walks through each of the six divisions in the order the examiner expects.

Why this matters for UPSC

UPSC Prelims has asked physiography-based questions in every year since 2011 — typically 1-3 questions on peaks, ranges, passes, plateaus, or coastal features. Mains GS-I (Geography) has asked direct divisions-vs-divisions comparison in 2014, 2016, 2019, and 2023. This is also the foundation layer for climate, soils, agriculture, biodiversity, and strategic geography questions — you cannot understand the monsoon without knowing the Himalayan barrier; you cannot understand cotton without knowing Deccan Trap basalt.