Sahyadri (Western Ghats)

Sahyadri (Western Ghats)
Name	Sahyadri (Western Ghats)
Country	India
States	Maharashtra; Karnataka; Goa; Kerala; Tamil Nadu
Highest	Anamudi
Elevation m	2695
Length km	1600

Sahyadri (Western Ghats) is a mountain range along the western coast of India that runs parallel to the Arabian Sea across the states of Maharashtra, Goa, Karnataka, Kerala, and Tamil Nadu. The range includes high peaks such as Anamudi, major passes like Bhor Ghat, and protected areas such as Periyar National Park, forming a UNESCO World Heritage Site recognized for exceptional biodiversity and endemism.

Geography and Extent

The Sahyadri extend ~1,600 km from the Tapti River in the north near Daman and Dadra and Nagar Haveli to the southern tip at Kanyakumari near Cape Comorin, separating the Deccan Plateau from the Konkan and the Malabar Coast. Notable physiographic subdivisions include the Konkan coastal belt, the Western Ghats escarpment with cliffs like Anjaneri and passes such as Thal Ghat, and plateaus like the Deccan Traps-derived Karnataka Plateau and the Nilgiri Hills. Major cities and urban centers adjacent to the range include Mumbai, Pune, Bengaluru, Mangalore, and Thiruvananthapuram, while river systems such as the Godavari, Narmada, Kaveri, and Tapi originate or are influenced by the range.

Geology and Formation

The Western Ghats are a product of the Deccan Traps flood basalt province, formed during the end-Cretaceous Deccan Traps eruption contemporaneous with the Chicxulub impact interval and the K-Pg extinction event. Tectonic uplift associated with the breakup of Gondwana and the northward drift of the Indian Plate created the escarpment, while later fluvial incision by rivers like the Periyar River and Sharavathi River sculpted valleys and gaps such as Agumbe and Jog Falls. Rock types include layered basalt flows, lateritic caps formed under monsoon weathering regimes, and remnant hill streams that reveal palaeoclimatic signals studied by researchers from institutions such as the Indian Institute of Science, CSIR-National Geophysical Research Institute, and Wadia Institute of Himalayan Geology.

Climate and Hydrology

The range intercepts southwest monsoon winds from the Arabian Sea producing orographic rainfall that feeds perennial rivers like the Godavari, Krishna, and Kaveri and seasonal tributaries including the Shimsha River and Netravati River. Microclimates range from wet evergreen zones in the Nilgiri Biosphere Reserve and Silent Valley to montane shola forests and grasslands near Anamudi, influenced by phenomena studied at Indian Meteorological Department observatories and research by National Centre for Medium Range Weather Forecasting. Major impoundments and hydropower projects such as the Bhakra Dam (indirectly related via river systems), Sasthamcotta Lake, and Idukki Dam alter flow regimes, while waterfalls like Dudhsagar Falls and Jog Falls exemplify the hydrological expression of escarpment topography.

Biodiversity and Ecosystems

The Western Ghats host tropical evergreen forests, semi-evergreen forests, deciduous forests, montane grasslands, and riparian habitats supporting endemic taxa such as Lion-tailed macaque, Nilgiri tahr, Malabar giant squirrel, and plant genera like Strobilanthes and Paliurus in localized assemblages. Birdlife includes species documented in surveys by Bombay Natural History Society and Salim Ali Centre for Ornithology and Natural History—notably Great Indian Hornbill and Nilgiri woodpigeon—while amphibian diversity features endemic families recorded by researchers at Jawaharlal Nehru University and University of Calicut. Protected areas and reserves such as Sanjay Gandhi National Park, Bandipur National Park, Wayanad Wildlife Sanctuary, Kudremukh National Park, and Eravikulam National Park conserve representative ecosystems and corridors cited in assessments by IUCN and UNESCO.

Human History and Culture

Human habitation and cultural landscapes in the Western Ghats include ancient trade routes connecting the Deccan Sultanates, Vijayanagara Empire, and Chola dynasty, with hill forts like Raigad and Rajmachi reflecting medieval polity and military architecture. Indigenous communities such as the Toda people, Kota people, Malayaraya, and Kuruba maintain traditional knowledge systems, agroforestry practices, and rituals tied to sacred groves recognized by scholars at Tata Institute of Social Sciences and Anthropological Survey of India. Colonial-era enterprises—plantations of tea, coffee, and rubber—established by interests linked to British India reshaped land use, while modern infrastructure projects intersect with cultural sites studied under programs at Archaeological Survey of India and Ministry of Environment, Forest and Climate Change.

Conservation and Threats

Conservation responses include designation of biodiversity hotspots by Conservation International, creation of protected networks like Nilgiri Biosphere Reserve and Western Ghats Ecology Expert Panel recommendations, and community initiatives by organizations such as Kalpavriksh and Nature Conservation Foundation. Major threats comprise deforestation driven by plantation agriculture expansion, fragmentation from highways like the National Highway 66 and Golden Quadrilateral, invasive species documented by Botanical Survey of India, and climate change impacts assessed by Intergovernmental Panel on Climate Change scenarios. Ongoing strategies emphasize corridor restoration, legal protections under instruments administered by the Forest Survey of India and judicial interventions from the Supreme Court of India, while transdisciplinary research continues at institutions including Indian Council of Forestry Research and Education and Centre for Ecological Sciences.

Category:Mountain ranges of India Category:Ecology of India