Mains Practice Questions

Introduction:

The intersection of land resource pressure and ecological stress has made land degradation and desertification a critical challenge for India.

• According to the ISRO Desertification and Land Degradation Atlas (2021), nearly 29.7% of India's total geographical area is undergoing degradation during 2018-19, with recent data indicating an upward trend in these processes.

Body:

Geographical Factors Influencing Patterns of Degradation

• Climatic Variations (Aridity & Rainfall):
  • Arid and Semi-Arid Zones: Regions like Western Rajasthan and Kutch face Wind Erosion due to low precipitation and high evapotranspiration.
    • Strong summer winds displace sandy topsoil, leading to the expansion of sand dunes.
  • High-Intensity Rainfall Belts: In the Western Ghats and Northeast India, heavy monsoonal rain on steep slopes triggers Water Erosion.
    • This washes away the nutrient-rich topsoil, often resulting in "lateritization" (hardening of soil).
• Topography and Geomorphology:
  • Hilly and Mountainous Terrains: The Himalayas are prone to mass wasting and landslides. Increasing slope instability, exacerbated by tectonic fragility and recent extreme rainfall events (e.g., Himachal and Uttarakhand 2023-25), leads to severe "Gully Erosion."
  • Coastal Geomorphology: Rising sea levels and cyclonic surges lead to Salinity Intrusion in the Sundarbans and coastal Odisha, turning fertile paddy fields into barren saline patches.
• Soil Texture and Composition:
  • Sandy soils in the Northwest have poor water-holding capacity, making them susceptible to desertification.
    • Conversely, the clayey "Black Cotton Soils" of the Deccan Plateau face Waterlogging when over-irrigated, leading to secondary salinization.

Processes of Land Degradation in India

The degradation process is often a "synergistic" outcome of geographical vulnerability and anthropogenic pressure.

• Water Erosion (Widespread): The most dominant process in India, particularly in the Indo-Gangetic plains and central highlands. It involves sheet, rill, and gully erosion, resulting in "Badland Topography" (e.g., Chambal Ravines).
• Vegetation Degradation: Loss of forest cover due to logging, forest fires, or Shifting Cultivation (Jhum) in the Northeast reduces soil anchoring, accelerating the cycle of degradation.
• Wind Erosion: Predominantly affects the Thar Desert. Recent shifts in wind patterns due to climate change have increased the frequency of "Dust Storms" (Andhi), transporting desert conditions to fringes of Haryana and Punjab.
• Salinization and Alkalization: Primarily an "irrigation-induced" process in the Green Revolution belt (Punjab, Haryana, Western UP). Excessive groundwater use and poor drainage lead to the accumulation of salts (locally called Reh or Kallar).

Recent Challenges and Ecological Stress

• Climate-Induced "Flash Droughts": Rapid depletion of soil moisture due to sudden temperature spikes has introduced degradation in traditionally sub-humid zones like Eastern Vidarbha and Jharkhand.
• Invasive Alien Species: Aggressive spread of Prosopis juliflora and Lantana camara in degraded patches has choked native biodiversity and altered soil chemistry, making natural restoration difficult.
• Groundwater Exhaustion: About 60% of districts are now groundwater-stressed. The resulting "drying of the sub-soil" causes land subsidence and loss of microbial life.
• Urban Sprawl and "Heat Islands": Rapid conversion of peri-urban agricultural land into "Impervious Surfaces" (concrete) disrupts natural drainage, increasing local runoff and erosion.

Strategic Measures for Restoration

• Mechanical/Engineering Measures
  • Contour Bunding & Trenching: Constructing embankments (bunds) or digging trenches along the lines of equal elevation (contours) to trap rainwater and prevent it from washing away topsoil.
  • Gully Plugging: Using boulders, sandbags, or vegetation to create "mini-dams" in gullies. This slows down water flow and allows silt to settle, gradually filling the gully.
  • Terracing: Converting steep slopes into a series of flat platforms (steps). This is essential in the Himalayas and Western Ghats to make hilly terrain cultivable without massive erosion.
  • Windbreaks and Shelterbelts: Planting rows of trees or shrubs perpendicular to the prevailing wind direction. This reduces wind speed at the ground level, preventing "blow-offs" in arid regions like Rajasthan.
• Biological and Agronomic Measures
  • Afforestation & Re-vegetation: Planting native species to bind the soil. Under the Green India Mission (GIM), the focus has shifted from "planting trees" to "restoring ecosystems."
  • Agroforestry: Integrating trees and shrubs into crop and livestock farming systems. This provides a "perennial cover" to the soil, reducing thermal stress and erosion.
  • Stubble Mulching: Leaving crop residue on the field after harvest. This acts as a protective layer against rain-splash and wind, while also adding organic carbon as it decomposes.
  • Crop Rotation & Intercropping: Growing soil-depleting crops (like cereals) with soil-building crops (like legumes/pulses) to maintain nutrient balance and ground cover.

Conclusion

Land degradation in India reflects a fragile balance disrupted by both natural forces and human pressures. Addressing it through an integrated landscape approach is essential amid rising climate risks and groundwater stress. Achieving Land Degradation Neutrality by 2030, restoring 26 million hectares, is vital for ensuring food security and strengthening rural resilience.