Western Ghats

The Western Ghats, a discontinuous chain of mountains extending roughly 1,600 km along India’s western coastline from Gujarat’s Junagadh district to Kanyakumari in Tamil Tamil Nadu, constitute one of the planet’s most biologically rich and geologically ancient landscapes. Recognised as a UNESCO World Heritage Site in 2012, the range harbours more than 7,400 species of flowering plants—about 30 % of which are endemic—alongside a staggering array of vertebrates and invertebrates found nowhere else on Earth. Its steep slopes, mist‑laden sholas, and deep river valleys create a mosaic of habitats that underpin both regional climate regulation and the water security of a quarter of India’s population.

Geological Origin and Evolution

The Western Ghats originated in the late Precambrian, about 1.6 billion years ago, as part of the ancient supercontinent Rodinia. Tectonic uplift during the breakup of Gondwana around 150 million years ago thrust the basaltic Deccan Traps eastward, forming the present‑day escarpments that rise 900 m to 1,600 m above sea level. Subsequent erosion sculpted the characteristic “step‑like” profile, while monsoonal rainwater carved deep gorges such as the Shivaji‑Ghat and the Nilgiri Hills. Geologists of the Geological Survey of India (GSI) have mapped over 2,000 distinct lithological units within the Ghats, reflecting a complex interplay of volcanic, sedimentary, and metamorphic processes.

Ecological Significance

The Western Ghats qualify as a Level 1 biodiversity hotspot under the criteria of Conservation International, hosting roughly 5,000 plant species, 1,200 bird species, 179 mammal species, and more than 6,000 insect taxa. Endemic vertebrates include the Nilgiri tahr (Nilgiritragus hylocrius), the lion‑tailed macaque (Macaca silenus), and the Malabar large‑flapped squirrel (Petinomys fuscocapillus). The range also shelters 200 amphibian species, representing 75 % of India’s total amphibian diversity, many of which are restricted to the shola‑grassland mosaics above 1,200 m. These ecosystems provide critical services: carbon sequestration of an estimated 0.5 Gt CO₂ per year, and pollination support for cash crops such as coffee and cardamom cultivated on the foothills.

Hydrological Role

Rainfall across the Ghats averages 2,000–5,000 mm annually, with the monsoon delivering up to 80 % of the total precipitation between June and September. The range’s catchment area feeds 12 major rivers—including the Godavari, Krishna, Kaveri, and the west‑flowing Narmada—supporting irrigation for over 30 million hectares of agricultural land. The Central Water Commission estimates that the Western Ghats’ waters supply drinking and domestic needs for roughly 40 % of India’s population, equivalent to more than 500 million people. Seasonal runoff from the Ghats also recharges the groundwater aquifers of Karnataka, Kerala, and Maharashtra, mitigating drought risk in the Deccan plateau.

Conservation and Threats

Despite its protected status, the Western Ghats face mounting pressures. Between 2000 and 2020, forest cover declined from 30 % to 24 % of the range’s area, primarily due to illegal logging, mining of bauxite and iron ore, and the expansion of hydroelectric projects such as the Sardar Sarovar dam. The 2018 Western Ghats Ecology Expert Panel (WGEEP) report, commissioned by the Ministry of Environment, Forest and Climate Change, identified 1,500 km² of “critical habitats” where biodiversity loss exceeds 30 % of baseline levels. In response, the National Biodiversity Authority (NBA) has instituted the “Western Ghats Conservation Blueprint,” which designates 44 wildlife sanctuaries, 12 national parks, and two biosphere reserves—Nilgiri and Silent Valley—as core protection zones. Community‑based initiatives, such as the Kudremukh Conservation Trust, now manage over 10 % of the remaining shola forests through participatory forest‑management agreements.

Cultural and Economic Importance

The Ghats have shaped human settlement for millennia, with archaeological sites like the Megalithic culture of the Bellary district dating back to 1,500 BCE. Indigenous groups such as the Todas, Kotas, and Irulas maintain traditional knowledge of medicinal plants, contributing to India’s pharmacopeia with over 1,200 documented herbal remedies. Economically, the range underpins a multi‑billion‑dollar tourism sector: wildlife safaris in Bandipur, tea plantations in Munnar, and trekking routes across the Western Ghats attract more than 2 million domestic and international visitors annually. Moreover, the Ghats’ agro‑forestry systems produce 30 % of the nation’s coffee and 15 % of its spice output, linking biodiversity with livelihoods across eight states.