BharatNotes Heat Island Effect
The phenomenon where urban areas experience significantly higher temperatures than surrounding rural areas due to dark impervious surfaces, reduced vegetation, waste heat from vehicles and air conditioning, and reduced evapotranspiration.
Context & Background
Documented since the early 19th century; increasingly severe with urban expansion; relevant to India's heatwave-urban interaction.
UPSC Exam Relevance
Heatwave definition (IMD — temperature ≥40°C in plains; ≥30°C in hills; or 4.5°C above normal); Heat Action Plans (Ahmedabad's HAP was India's first, 2013); NDMA heatwave guidelines.
