Alarming Environmental Decline in the Aravallis

Context:

A recent scientific study has exposed the severe environmental repercussions of ongoing land use changes in the Aravallis. The study reveals that the continuous destruction of these hills is causing significant biodiversity loss, soil degradation, and a decline in vegetation cover, signaling an urgent need for comprehensive conservation strategies to reverse these damaging trends.

Relevance:

GS III: Environment and Ecology

Dimensions of the Article:

1. Challenges Facing the Aravallis
2. Enhanced Vegetation Index (EVI) Explained
3. Future Projections and Biodiversity
4. Aravalli Range

Challenges Facing the Aravallis

• Loss of Land: Between 1975 and 2019, about 8% (5,772.7 sq km) of the Aravalli region was lost, including 5% turned into barren land and 1% into settlements.
• Environmental Impact: This degradation facilitated the expansion of the Thar Desert towards the National Capital Region, increasing desertification and erratic weather patterns.
• Mining Expansion: The area used for mining increased from 1.8% in 1975 to 2.2% in 2019, contributing significantly to the degradation of the Aravalli hills.
• Urbanization and Mining: Rapid urbanization alongside unchecked mining practices are major factors in the degradation, with over 25% of the Aravallis lost to illegal quarrying.
• Air Pollution: Mining activities significantly contribute to air pollution in the NCR, particularly through respirable particulate matter (RPM).
• Decline in Forest Cover: The central range’s forest cover has reduced by 32% from 1975 to 2019, paralleled by an increase in cultivated land.
• Water Resource Impact: Mining activities have disrupted aquifers, altering water flows, drying up lakes, and creating new water bodies.
• Protected Areas’ Impact: Wildlife sanctuaries like Todgarh-Raoli and Kumbhalgarh have positively impacted the eco-sensitive zones, showing minimal forest depletion.
• Enhanced Vegetation Index (EVI): EVI least value of 0 to -0.2 in upper central Aravali region (Nagaur district) – indicating unhealthy vegetation.

Enhanced Vegetation Index (EVI) Explained

• EVI Overview: EVI is an advanced vegetation index designed for higher sensitivity to biomass, atmospheric conditions, and soil quality, serving as a modified version of the Normalized Difference Vegetation Index (NDVI).
• EVI Significance: The index ranges from 0 to 1, where values closer to 1 indicate healthier vegetation, while values closer to 0 suggest unhealthy vegetation, providing a crucial tool for environmental monitoring.

Future Projections and Biodiversity

• Projected Loss: By 2059, it is projected that 22% of the Aravalli area could be lost, with 3.5% potentially used for mining purposes.
• Biodiversity Decline: There has been a significant decrease in local wildlife, including leopards, striped hyenas, and golden jackals.
• River Impacts: Key rivers originating from the Aravallis, such as Banas, Luni, Sahibi, and Sakhi, are now dead, reflecting the severe environmental stress in the region.
• Human-Wildlife Conflicts: The loss of natural forests has escalated conflicts between humans and wildlife in the area, highlighting the urgent need for conservation and sustainable management strategies.

Aravalli Range

• The Aravalli Range extends 692 km from Gujarat to Delhi, passing through Rajasthan, with a width ranging from 10 to 120 km.
• Approximately 80% of the range is situated within Rajasthan, with the remaining 20% spread across Haryana, Delhi, and Gujarat.
•  The range is segmented into two primary sections: the Sambhar Sirohi Range and the Sambhar Khetri Range in Rajasthan, spanning about 560 km.
• The Aravallis serve as an ecotone, acting as a transition zone between the Thar Desert and the Gangetic Plain, where diverse ecosystems and biological communities converge.
• Gurusikhar, located in Rajasthan, is the highest peak of the Aravallis, standing at an elevation of 1,722 meters.

Significance of the Aravallis

• The Aravallis play a crucial role in halting the advancement of the Thar Desert towards the fertile Indo-Gangetic plains, also serving as vital catchment areas.
• Home to 300 native plant species and 120 bird species, the range is a sanctuary for various animals, including jackals and mongooses.
• During the monsoon season, the Aravallis guide monsoon clouds eastward, benefiting the sub-Himalayan rivers and North Indian plains, while in winter, they protect the fertile valleys from harsh westerly winds.
• The range significantly contributes to groundwater replenishment by capturing rainwater, thereby enhancing the groundwater levels.
• Often referred to as the “lungs” of Delhi-NCR, the Aravallis mitigate some of the severe air pollution effects experienced in the region.

-Source: Down To Earth