Key Facts & Data Points

  • NH‑GCI: National Highways Green Cover Index, measuring % green canopy within each 1 km highway segment.
  • Coverage: ~30,000 km of National Highways in 24 states (O&M phase).
  • Satellites Used: 5‑m resolution multispectral data from ISRO’s Resourcesat‑2/2A (LISS‑IV); cross‑verified with finer Cartosat‑2S imagery.
  • Data Portal: Interactive maps and reports on ISRO’s Bhuvan web‑GIS platform.
  • Policy Linkage: Implements the Green Highways Policy, 2015 – mandates tree planting and survival monitoring.
  • Future Enhancements: Machine‑learning based auto‑classification, change‑detection alerts, integration with carbon‑sequestration models.

Background & Context

  • The Green Highways Policy was introduced to curb environmental degradation caused by road expansion and to promote ecological corridors.
  • Traditional monitoring relied on ground surveys; the NH‑GCI leverages space‑based remote sensing for objective, large‑scale assessment.
  • Collaboration between NHAI and ISRO’s National Remote Sensing Centre (NRSC) marks a significant e‑governance initiative.

Significance for India / Governance / Policy

  • Environmental: Quantifies vegetation cover, aiding in carbon‑sequestration estimates and climate‑action reporting (SDG‑13, NDCs).
  • Infrastructure Planning: Provides data for route‑realignment, afforestation drives, and maintenance of green corridors.
  • E‑Governance: Open‑source GIS portal ensures transparency and public accessibility of environmental data.
  • Economic: Potential to generate carbon credits and attract green financing for highway projects.

Related Constitutional / Legal Provisions

  • Article 48A of the Constitution (State’s duty to protect the environment) supports green infrastructure initiatives.
  • National Forest Policy, 1988 and Forest (Conservation) Act, 1980 provide legal backing for afforestation along public works.

Technological Framework

  • Remote Sensing: Multispectral imaging captures chlorophyll content, enabling canopy density calculations.
  • GIS Integration: Bhuvan platform overlays satellite data with highway GIS layers for spatial analysis.
  • Machine Learning (Planned): Automates vegetation classification, detects loss, and triggers alerts.

Future Scope & Recommendations

  • Integrate carbon‑sequestration models to quantify CO₂ mitigation per kilometre.
  • Expand monitoring to newly constructed highway stretches and state highways.
  • Link NH‑GCI data with urban planning to create continuous green belts.
  • Encourage public‑private partnerships for maintenance of planted trees.

Reference: Green National Highways Corridor Project