The Aravallis as a Natural Shield Against Desertification

Syllabus: GS3: Environment and Ecology

Context

• A recent dust storm in Rajasthan’s regions highlighted the crucial ecological role of the Aravalli Range in shielding northern India from dust storms.

Dust Storms  in Northwestern India

• Dust storms frequently occur in northwestern India during the pre-monsoon months of April to June.
• Intense heating of the land surface creates dry and unstable atmospheric conditions that favor the formation of dust storms.
  • Strong south-westerly and westerly winds transport large quantities of dust from the Thar Desert and adjoining regions towards northern India.

How Do the Aravallis Protect Northern India?

• The Aravalli Range, stretching over approximately 692 kilometres (430 miles) in a northeastern direction, traverses the Indian states of Gujarat, Rajasthan, and Haryana before culminating in Delhi, is the oldest mountain range in India.
  • Rajasthan accounts for nearly two-thirds of the mountain range.
• The Aravallis support water-recharge systems and are the source of rivers such as the Sabarmati and Luni.
• The region is rich in minerals including sandstone, limestone, marble, granite, lead, zinc, copper, gold, and tungsten.
• Significance: The Aravalli Range acts as a natural barrier between the Thar Desert and the densely populated Indo-Gangetic Plains.
  • Dust-laden winds lose their speed when they encounter the Aravalli hills, causing sand and dust particles to settle on the western slopes.
  • The presence of forests and vegetation further reduces the movement of dust by trapping airborne particles.
  • The range helps prevent the eastward expansion of desert conditions and protects agricultural and urban regions from excessive dust deposition.

What Is Causing the Degradation of the Aravallis?

• Extensive mining of granite, red silica, marble, and other minerals has damaged hills and natural landscapes across the range.
• Removal of forests and natural vegetation has reduced the capacity of the Aravallis to trap dust and stabilize soils.
• Conversion of forest and grazing lands into settlements and agricultural areas has weakened ecological resilience.

Source: IE