The Union government’s decision to redefine the Aravalli Hills has triggered protests, legal scrutiny, and fears of long-term ecological damage. While the Environment Ministry insists there is “no imminent threat” and that mining would be permitted in only a tiny fraction of the range, critics argue that the new definition fundamentally alters how the Aravallis are recognised—and protected—across four states.
What Has Changed in the Aravalli Definition
Under a new definition approved by the Supreme Court on November 20, landforms will qualify as part of the Aravalli Hills only if they rise at least 100 metres above the local relief, meaning their immediate surrounding terrain. Their slopes and adjacent areas would also be included.
This marks a departure from earlier approaches that relied on standardised baselines, such as the Forest Survey of India’s method of identifying Aravalli areas using a minimum elevation benchmark and a 3-degree slope criterion. The shift to “local relief” as a reference point significantly narrows what qualifies as Aravalli terrain.
Why the 100-Metre Benchmark Is Controversial
Using local relief rather than a uniform baseline can exclude large hill systems if their surrounding areas are already at higher elevations. As a result, many hillocks and undulating tracts that function ecologically as part of the Aravalli range may lose formal recognition.
In Rajasthan alone—home to nearly two-thirds of the Aravallis—this change could exclude over 99% of the hills earlier identified by the Forest Survey of India in 15 districts. Critics argue this is not a technical correction but a substantial rollback of ecological safeguards.
What Remains Protected Despite the Redefinition
The government maintains that strong protections remain intact. Areas already designated as tiger reserves, national parks, wildlife sanctuaries, eco-sensitive zones, wetlands, and compensatory afforestation plantations continue to be governed by existing forest and wildlife laws.
However, such protections are not immutable. Past attempts to “rationalise” the boundaries of protected areas—such as around Sariska—have shown how administrative revisions can open doors to mining and development unless judicially checked.
Mining Claims Versus Ground Realities
Union Environment Minister Bhupender Yadav has stated that mining would be allowed in only 0.19% of the Aravalli’s “1.44 lakh sq km” area. Environmental experts counter that this figure is misleading, as it reflects the total landmass of 34 districts labelled as Aravalli districts—not the actual hill range.
Under the Forest Survey of India’s assessment, the Aravallis span about 40,483 sq km in Rajasthan, a far smaller and more ecologically meaningful figure. Reducing the legally recognised extent automatically shrinks the zone where mining and large-scale construction are restricted.
Districts and Landscapes Left Out
Several historically and ecologically significant districts do not feature in the new Aravalli list submitted to the Supreme Court. These include Sawai Madhopur, home to Ranthambhore Tiger Reserve at the Aravalli–Vindhya junction; Chittorgarh, known for its UNESCO-listed fort on an Aravalli outcrop; and Nagaur, where the Forest Survey of India mapped over 1,100 sq km of Aravalli terrain.
Their exclusion raises questions about how cultural heritage, biodiversity corridors, and watershed functions will be safeguarded.
Beyond Mining: Wider Environmental Implications
The consequences of the new definition extend beyond mining. In Delhi-NCR, where the Aravalli ranges taper into lower hills, many tracts could lose Aravalli status altogether. This may unlock large parcels of land for real estate development, intensifying urban heat, air pollution, and groundwater stress.
Illegal mining—already a major issue—could also become harder to regulate if vast areas are formally declassified as Aravalli, weakening the legal basis for enforcement.
What the Centre Told the Supreme Court
The Environment Ministry informed the Supreme Court that the 100-metre definition would include a larger area than the Forest Survey’s slope-based method, arguing that average slopes in several Aravalli districts fall below 3 degrees. Critics point out that district-level averages obscure the presence of ecologically critical hill systems within largely plain regions.
The emphasis, observers note, appears to be on avoiding “inclusion errors” rather than preventing large-scale exclusion of fragile landscapes.
A Larger Question of Environmental Governance
At the heart of the controversy lies a broader governance dilemma: should environmental definitions err on the side of maximal ecological protection or administrative convenience? The Aravallis are not just hills but a lifeline—regulating climate, recharging aquifers, and acting as a barrier against desertification and pollution in north-west India.
Redrawing their boundaries has implications that will unfold over decades, long after immediate assurances about mining percentages fade from public memory.
What to Note for Prelims?
- Aravalli Range: states covered and ecological role
- Forest Survey of India’s 3-degree slope method
- New 100-metre local relief definition
- Eco-sensitive zones and legal protections
What to Note for Mains?
- Impact of definitional changes on environmental protection
- Centre–state–judiciary dynamics in conservation policy
- Mining, urbanisation, and ecological security in Aravallis
- Balancing development with long-term environmental governance
