Relevance for UPSC: GS I (Geography), GS III (Science & Technology, Environment, Disaster Management); Source: The Hindu

Context

Remote sensing technology allows governments and scientists to map forests, water resources, and mineral deposits without physical contact. 

By using satellites and sensors, it supports sustainable management of natural resources—crucial for India amid climate stress, rapid urbanisation, and rising resource demand.

Core Concept: Remote Sensing

Remote sensing is the science of collecting information about Earth’s surface from a distance using sensors mounted on satellites, aircraft, or drones. 

These sensors record electromagnetic radiation reflected or emitted by land, water, and vegetation. Each surface has a unique spectral signature, enabling identification and mapping.

Key Applications

• Forests: Mapping forest cover, degradation, carbon sinks.
• Water: Locating groundwater aquifers, monitoring wetlands and droughts.
• Minerals: Identifying mineral-rich zones using rock reflectance patterns.
• Disasters: Flood mapping, landslide zonation, cyclone damage assessment.

Limitations

• Cloud cover affects optical sensors.
• Requires skilled interpretation and ground verification.
• High initial costs and data-integration challenges.

Conclusion

Remote sensing converts invisible Earth processes into actionable data, enabling evidence-based governance, disaster resilience, and sustainable resource management.

Q. Which remote sensing technique is most suitable for mapping groundwater under dense vegetation?
A. Optical remote sensing
B. Thermal remote sensing
C. Microwave (Radar) remote sensing
D. Ultraviolet remote sensing

Correct Answer: C