BharatNotes
Overview
The Western Ghats (Sahyadri) and Eastern Ghats are two parallel hill ranges flanking the Deccan Plateau — the Western Ghats running along the Arabian Sea coast, the Eastern Ghats along the Bay of Bengal coast. Together they form the backbone of peninsular India's river systems, biodiversity, and climate. The Western Ghats is one of the world's eight biodiversity "hottest hotspots" and a UNESCO World Heritage Site (2012). For UPSC, these ranges are tested across Prelims (geography facts) and Mains (GS1 — biodiversity, environment policy).
Western Ghats — Key Facts
| Feature | Details |
|---|---|
| Other name | Sahyadri Mountains |
| Length | ~1,600 km — from the Tapti River (Gujarat-Maharashtra border) to Kanyakumari (Tamil Nadu) |
| Width | 50–80 km (average) |
| Highest peak | Anamudi (2,695 m) — Kerala; highest peak in India south of the Himalayas |
| States covered | Gujarat, Maharashtra, Goa, Karnataka, Kerala, Tamil Nadu |
| Average elevation | 1,200 m (general crest), rising to 2,695 m at Anamudi |
| UNESCO status | World Heritage Site inscribed in 2012 — 39 component sites across 7 sub-clusters |
UNESCO World Heritage — 39 Component Sites
The Western Ghats serial nomination (2012) comprises 39 component sites distributed across four states — 20 in Kerala, 10 in Karnataka, 6 in Tamil Nadu, and 3 in Maharashtra — grouped into 7 sub-clusters. The serial nomination was used because no single contiguous site could capture the full range of biodiversity across this 1,600 km range.
Key protected areas within the UNESCO nomination include Nilgiri Biosphere Reserve, Silent Valley National Park, Kudremukh National Park, Periyar Tiger Reserve, and Agasthyamalai Biosphere Reserve.
Rivers Originating in the Western Ghats
The Western Ghats form one of India's principal watersheds, feeding rivers that drain nearly 40% of the country's land area:
| River | States Drained | Key Feature |
|---|---|---|
| Godavari | Maharashtra, Telangana, Andhra Pradesh | Originates near Trimbakeshwar (Nashik); India's second longest river |
| Krishna | Maharashtra, Karnataka, Andhra Pradesh | Originates at Mahabaleshwar (1,336 m altitude); 1,400 km long |
| Cauvery (Kaveri) | Karnataka, Tamil Nadu | Originates at Talakaveri, Brahmagiri Hills, Coorg; the "Ganga of the South" |
| Tungabhadra | Karnataka | Major Krishna tributary; flows eastward; Hampi on its banks |
| Periyar | Kerala | Flows westward into the Arabian Sea; Periyar Tiger Reserve |
| Sharavathi | Karnataka | Jog Falls (253 m drop) — India's highest plunge waterfall |
A key feature is the Western and Eastern watershed divide: rivers originating on the western slope of the Ghats (e.g., Periyar, Netravati) are short, fast, and drain westward into the Arabian Sea, while rivers originating on the eastern slope (Godavari, Krishna, Cauvery) are long, slow-moving, and drain eastward into the Bay of Bengal.
Western Ghats as a Biodiversity Hotspot
The Western Ghats is recognised as one of the world's 36 biodiversity hotspots (Conservation International classification). It supports extraordinary species diversity, most of it endemic:
| Category | Number of Species | Endemism (approx.) |
|---|---|---|
| Flowering plants | ~5,000 | ~1,700 endemic |
| Amphibians | ~179 | ~87% endemic |
| Reptiles | ~157 | ~62% endemic |
| Birds | ~508 | ~16% endemic |
| Mammals | ~139 | ~12% endemic |
Notable endemic species include the Lion-tailed Macaque, Nilgiri Tahr (State animal of Tamil Nadu), Malabar Giant Squirrel, Nilgiri Langur, Malabar civet, and numerous endemic frogs and fish of the Western Ghats.
Hill Stations
| Hill Station | State | Elevation | Notable Feature |
|---|---|---|---|
| Ooty (Udhagamandalam) | Tamil Nadu | 2,240 m | Nilgiri Mountain Railway (UNESCO Heritage); former Madras summer capital |
| Munnar | Kerala | ~1,600 m | Tea plantations; Eravikulam NP (Nilgiri Tahr) |
| Kodaikanal | Tamil Nadu | 2,100 m | Star-shaped lake; shola forests; Kurinji flower (blooms every 12 years) |
| Coorg (Kodagu) | Karnataka | ~1,200 m | Coffee and spice estates; Kodava culture |
| Mahabaleshwar | Maharashtra | 1,353 m | Origin of Krishna River; strawberry cultivation |
| Lonavala | Maharashtra | ~624 m | Gateway to Sahyadri for Mumbai-Pune corridor |
Eastern Ghats — Key Facts
| Feature | Details |
|---|---|
| Nature | Discontinuous — broken by river valleys; not a continuous range like Western Ghats |
| Length | ~1,750 km — from Odisha to Tamil Nadu (some estimates include Gujarat segment) |
| Average elevation | ~600 m (significantly lower than Western Ghats) |
| Highest peak | Arma Konda (1,680 m), Visakhapatnam district, Andhra Pradesh |
| Other significant peaks | Mahendragiri (1,501 m, Odisha-Andhra border); Jindhagada Peak (1,690 m, Andhra Pradesh) |
| States covered | Odisha, Andhra Pradesh, Tamil Nadu |
The Eastern Ghats are separated by the Mahanadi, Godavari, Krishna, and Cauvery river valleys as they flow east, giving the range its characteristic discontinuous appearance. The terrain is lower, drier, and ecologically distinct from the wet, continuous Western Ghats.
Western Ghats vs Eastern Ghats — Comparison
| Feature | Western Ghats | Eastern Ghats |
|---|---|---|
| Continuity | Continuous range | Discontinuous, broken by rivers |
| Length | ~1,600 km | ~1,750 km (discontinuous) |
| Average elevation | ~1,200 m | ~600 m |
| Highest peak | Anamudi, 2,695 m (Kerala) | Arma Konda, 1,680 m (Andhra Pradesh) |
| Rainfall | Very heavy (windward side gets 2,500–5,000 mm); rain shadow on leeward side | Moderate (600–1,000 mm); receives NE monsoon |
| Forests | Tropical wet evergreen and semi-evergreen | Tropical dry deciduous |
| Rivers | Source of Godavari, Krishna, Cauvery, Periyar | Cut through by major rivers |
| UNESCO status | World Heritage Site (2012) | Not designated |
| Biodiversity | Hotspot (globally recognized) | Significant but less endemic |
Threats to Western Ghats
The Western Ghats faces multiple anthropogenic threats:
- Deforestation and habitat fragmentation: Expansion of tea, coffee, cardamom, and eucalyptus plantations; road widening projects (NH 66, NH 544)
- Mining: Iron ore and bauxite mining in Goa and Karnataka (Kudremukh controversy)
- Hydropower projects: Large dams (Silent Valley, Athirappilly) threatening river ecosystems and forest integrity
- Invasive species: Lantana camara and Eupatorium have colonised degraded forest edges
- Western Ghats Ecology Expert Panel (WGEEP/Gadgil Committee, 2011): Recommended declaring 64% of Western Ghats as Ecologically Sensitive Area (ESA); modified by Kasturirangan Committee (2013), which recommended ESA status for 37% (~60,000 km²)
The Kasturirangan report (2013) recommendations remain partially implemented — a long-running controversy over balancing conservation with local livelihoods in six states.
Exam Strategy
Prelims Focus:
- Anamudi (2,695 m) — highest peak south of Himalayas (Western Ghats, Kerala)
- UNESCO inscribed in 2012 — 39 component sites
- Western Ghats = continuous; Eastern Ghats = discontinuous
- Arma Konda (1,680 m) — highest peak of Eastern Ghats (Andhra Pradesh)
- Rivers: Godavari, Krishna, Cauvery originate in Western Ghats
- Jog Falls = on the Sharavathi River
Mains Focus:
- Western Ghats as a biodiversity hotspot: endemism, fragility, WGEEP vs Kasturirangan recommendations
- Comparison of Western and Eastern Ghats: structure, ecology, rivers
- Environmental threats and the ESA debate — balancing conservation with development
- Importance of Western Ghats for India's water security (feeds rivers draining 40% of land area)
Sources: UNESCO World Heritage Centre (whc.unesco.org — Western Ghats, list 1342); IUCN World Heritage Outlook; WWF India (wwfindia.org); MoEFCC — Western Ghats Ecology Expert Panel Report (Gadgil, 2011); Kasturirangan Committee Report (2013); Wikipedia (Western Ghats, Eastern Ghats, Arma Konda)
