What is the Deccan Plateau?

The Deccan Plateau is a large triangular plateau occupying the majority of peninsular India, extending over an area of approximately 422,000 sq. km (163,000 sq. miles). It is bounded by the Satpura and Vindhya ranges to the north, the Western Ghats (Sahyadris) to the west, the Eastern Ghats to the east, and tapers southward toward the Nilgiri Hills in Tamil Nadu. The name "Deccan" derives from the Sanskrit word Dakshin meaning "south".

The plateau has an average elevation of about 600 metres (2,000 ft) and slopes gently from west to east, which is why most major peninsular rivers -- the Godavari, Krishna, Kaveri, and Mahanadi -- flow eastward into the Bay of Bengal. Exceptions include the Narmada and Tapti, which flow westward through rift valleys into the Arabian Sea.

A defining geological feature is the Deccan Traps in the northwestern portion -- one of the largest volcanic provinces on Earth. Formed by massive basaltic lava flows about 66 million years ago (coinciding with the end-Cretaceous extinction), the Traps cover approximately 500,000 sq. km with basalt layers more than 2 km thick in places. These basaltic rocks have weathered to form the fertile black cotton soil (regur) -- rich in clay, moisture-retentive, and ideal for cotton cultivation.

Key Features

# Feature Details
1 Area ~422,000 sq. km
2 Average Elevation ~600 m (2,000 ft)
3 General Slope West to East
4 Northern Boundary Satpura-Vindhya Ranges and Narmada Valley
5 Western Boundary Western Ghats (Sahyadris)
6 Eastern Boundary Eastern Ghats
7 Major Rivers Godavari, Krishna, Kaveri, Mahanadi (eastward-flowing)
8 Deccan Traps Basaltic lava province (~66 mya); ~500,000 sq. km area
9 Dominant Soil Black cotton soil (regur) from weathered basalt

Current Status / Latest Data

  • The Deccan Plateau is subdivided into the Maharashtra Plateau, Karnataka Plateau, and Telangana-Rayalaseema Plateau.
  • The region is a major producer of cotton, sugarcane, jowar, and pulses, owing to fertile black soil.
  • The Western Ghats (a UNESCO World Heritage Site) form the western escarpment and are a biodiversity hotspot.
  • The plateau faces challenges of water scarcity (rain-shadow effect east of Western Ghats), soil erosion, and groundwater depletion in parts of Maharashtra, Karnataka, and Telangana.
  • Major urban centres on the plateau include Bengaluru, Hyderabad, Pune, and Nagpur.

UPSC Exam Corner

Prelims: Key Facts

  • Deccan Plateau area: ~422,000 sq. km; elevation: ~600 m
  • Slopes west to east -- rivers flow to Bay of Bengal
  • Deccan Traps: basaltic lava (~66 mya), one of the largest volcanic provinces
  • Black cotton soil (regur) formed from weathered basalt
  • Western Ghats are the water tower of peninsular India
  • Narmada and Tapti flow westward through rift valleys (exception to the eastward pattern)

Mains: Probable Themes

  1. Geological evolution of the Deccan Plateau -- Gondwana breakup, Deccan Traps volcanism, and their impact on present-day landforms
  2. River systems of the Deccan and the west-east asymmetry caused by the Western Ghats
  3. Water crisis in the rain-shadow regions and inter-state river water disputes (Krishna, Kaveri)
  4. Black soil properties and their significance for Indian agriculture
  5. Role of the Western Ghats as a biodiversity hotspot and its conservation challenges

Sources: Wikipedia - Deccan Plateau, Britannica - India: The Deccan, Wikipedia - Deccan Traps