They are one of the most ecologically significant regions of India. They extend along the western edge of the Deccan Plateau and play a decisive role in monsoon regulation, river systems, biodiversity conservation, and climate stability. They stretch across Gujarat, Maharashtra, Goa, Karnataka, Tamil Nadu, and Kerala, covering nearly 160,000 sq km, and support millions of people through water, forests, agriculture, and ecosystem services.
Location and Extent
- Run parallel to the western coast of India, from the Satpura Range in the north to Kanyakumari in the south
- Form the western boundary of the Deccan Plateau
- Known as Sahyadri in Maharashtra and Sahya Parvatham in Kerala
- Often described as the “Great Escarpment of India” due to steep western slopes and gentler eastern slopes
Geological Formation
The Western Ghats are among the oldest mountain systems in India and have a tectonic origin.
- Represent the western faulted edge of the Deccan Plateau, not true fold mountains
- Formed due to downwarping towards the Arabian Sea and tilting of the plateau
- Characterised by steep western cliffs and gentle eastern slopes
- Composed of diverse rock systems including basalt, granite gneiss, charnockite, khondalite, and leptynite
- Their ancient geology strongly influences drainage patterns, soil formation, and biodiversity
Major Divisions
The Western Ghats are commonly divided into three broad sections based on relief, climate, and vegetation.
Northern Western Ghats
- Extend mainly through Maharashtra
- Dominated by basaltic lava plateaus
- Important peaks include Kalsubai (highest in Maharashtra), Salher, and Mahabaleshwar
Central Western Ghats
- Cover Karnataka and parts of Goa
- Characterised by very high rainfall and dense evergreen forests
- Includes Malnad region and river basins of Sharavathi and Netravati
Southern Western Ghats
- Spread across Kerala and Tamil Nadu
- Include the Nilgiri, Annamalai, and Cardamom hills
- Region of highest elevations and biodiversity concentration
Important Mountain Ranges and Peaks
- Nilgiri Hills link the Western Ghats with the Eastern Ghats
- Anamudi (Kerala) is the highest peak of the Western Ghats and the highest mountain in India outside the Himalayas
- Prominent hill stations include Mahabaleshwar, Matheran, Panchgani, Lonavala–Khandala, Kodagu, Kudremukh, and Amboli
River Systems
The Western Ghats are the primary water divide of Peninsular India, giving rise to both west-flowing and east-flowing rivers.
West-Flowing Rivers
- Include Periyar, Sharavathi, Netravati, Mandovi, and Bharathappuzha
- Short, fast-flowing rivers with steep gradients
- Major source of hydropower, especially in Karnataka and Kerala
East-Flowing Rivers
- Major rivers like Godavari, Krishna, and Kaveri originate here
- Important tributaries include Tunga, Bhadra, Bhima, Malaprabha, Hemavathi, and Kabini
- Longer rivers supporting irrigation and agriculture across the Deccan Plateau
Climate and Environmental Role
- Act as a climatic barrier, intercepting moisture-laden southwest monsoon winds
- Cause heavy rainfall on western slopes and rain-shadow conditions on eastern slopes
- Support multiple forest types:
- Evergreen and semi-evergreen forests on western slopes
- Moist and dry deciduous forests on eastern slopes
- Play a key role in monsoon circulation and rainfall distribution over peninsular India
Biodiversity
The Western Ghats are one of the world’s most important biodiversity regions.
- Recognised as a UNESCO World Heritage Site
- Identified as one of the eight global biodiversity hotspots
- Home to over 325 globally threatened species
- High level of endemism, especially in amphibians, plants, and reptiles
- Iconic species include Nilgiri tahr, lion-tailed macaque, Nilgiri marten
- Protected areas include 2 biosphere reserves, 13 national parks, and numerous wildlife sanctuaries
- Nilgiri Biosphere Reserve is the largest contiguous protected forest landscape in India
Significance
- Source region for major rivers supplying water to peninsular India
- Regulate monsoons and stabilise regional climate
- Sequester around 4 million tonnes of carbon annually, nearly 10% of India’s forest carbon capture
- Support forest-based industries and agriculture
- Sustain indigenous and tribal communities through non-timber forest produce
Major Challenges
- Mining activities, especially in Goa and parts of Karnataka
- Deforestation and illegal logging
- Expansion of monoculture plantations such as tea, coffee, rubber, and oil palm
- Hydropower projects fragmenting ecosystems
- Encroachment by settlements and infrastructure
- Human–wildlife conflict and habitat loss
- Climate change increasing rainfall variability and flood frequency
Conservation Efforts
- Gadgil Committee (2011) recommended declaring the entire Western Ghats as Ecologically Sensitive Areas with graded restrictions
- Kasturirangan Committee (2013) proposed 37% of the Ghats as ESA with restrictions on mining and quarrying
- Expansion of protected areas through national parks and wildlife sanctuaries
- Focus on habitat restoration, regulation of development projects, and protection of endemic species
