Explained: What the Aravalli redefinition row is all about

New Delhi: The Aravalli hills, one of the world's oldest mountain ranges, have become the eye of a growing political storm over its new defining criteria and the environmental implications of the new definition.

Here is an explainer of what is happening and why.

1. What is the controversy about?

A committee of the Ministry of Environment, Forest and Climate Change (MoEFCC) recommended a change in the definition of the Aravalli hills and ranges to protect the world's oldest mountain system in October this year.

The Supreme Court accepted the recommendations last month but kept the order in abeyance on Monday.

2. What were the committee's recommendations?

The committee had recommended that the "Aravalli Hill" be defined as any landform in designated Aravalli districts with an elevation of 100 metres or more above its local relief, and an "Aravalli Range" will be a collection of two or more such hills within 500 metres of each other.

The committee, while defining the Aravalli hills, said, "Any landform located in the Aravalli districts, having an elevation of 100 metres or more from the local relief, shall be termed as Aravalli Hills... The entire landform lying within the area enclosed by such lowest contour, whether actual or extended notionally, together with the Hill, its supporting slopes and associated landforms irrespective of their gradient, shall be deemed to constitute part of the Aravalli Hills."

3. Opposition to the new definition of Aravallis

Activists, scientists and opposition alleged that the redefinition could open vast stretches of the fragile mountain ecosystem to mining. Those who opposed the Centre's new definition alleged that it was done without adequate scientific assessment or public consultation. So, it risks exposing large parts of the Aravallis across Haryana, Rajasthan and Gujarat to mining.

4. Importance of Aravallis

The Aravalli hills and ranges are among India's oldest geological formations, stretching from Delhi through Haryana, Rajasthan and into Gujarat. Historically, they have been recognised across 37 districts by state governments, with their ecological role noted as a natural barrier against northern desertification and a protector of biodiversity and water recharge.

The Supreme Court had in November emphasised that uncontrolled mining here poses a "great threat to the ecology of the nation" and directed uniform criteria to safeguard them. Their conservation is thus vital for ecological stability, cultural heritage, and sustainable development.

5. Ban on new mining leases

The Supreme Court had, on November 20, accepted a uniform definition of the Aravalli hills and ranges and banned the grant of fresh mining leases inside its areas spanning Delhi, Haryana, Rajasthan and Gujarat until experts' reports are out.

Following widespread concern over the implications of the new definition, the MoEFCC also announced a ban on new mining leases.

6. What would have remained protected as per the new definition?

Parts of Aravallis are designated as tiger reserves, national parks, sanctuaries, eco-sensitive zones around these protected areas, and wetlands and plantations under the compensatory afforestation scheme.

These areas remain out of bounds for mining or development, unless permitted specifically under the relevant wildlife and forest acts, irrespective of their status as Aravalli hills.