Model Answer
0 min readIntroduction
The rapid urbanization in India, driven by economic opportunities and population growth, has led to a significant transformation of the natural landscape. The ‘urban built environment’ – encompassing buildings, infrastructure, and paved surfaces – fundamentally alters the biophysical character of cities and their surrounding areas. As per the Census of India 2011, 31.16% of India’s population resides in urban areas, a figure projected to rise significantly. This expansion necessitates a detailed understanding of the ecological consequences of urban construction and planning, impacting everything from local climate to biodiversity.
Changes in the Biophysical Landscape
The urban built environment induces several key changes in the biophysical character of the landscape. These can be categorized as follows:
1. Alterations to Hydrological Cycle
- Increased Runoff: Impervious surfaces (roads, buildings) prevent rainwater infiltration, leading to increased surface runoff. This contributes to urban flooding, erosion, and reduced groundwater recharge. For example, Chennai floods of 2015 were exacerbated by extensive concretization.
- Reduced Evapotranspiration: Vegetation cover is replaced by concrete, reducing evapotranspiration and altering local humidity levels.
- Water Pollution: Runoff carries pollutants (oil, chemicals, sewage) into water bodies, degrading water quality.
2. Impact on Soil Characteristics
- Soil Sealing: Construction directly seals the soil, rendering it unproductive and disrupting natural soil processes.
- Soil Compaction: Heavy machinery and construction activities compact the soil, reducing its porosity and water-holding capacity.
- Soil Contamination: Construction debris and industrial waste contaminate the soil with harmful chemicals.
3. Modifications to Air Quality and Climate
- Urban Heat Island (UHI) Effect: Dark surfaces absorb more solar radiation, leading to higher temperatures in urban areas compared to surrounding rural areas. This is particularly pronounced in cities like Delhi and Mumbai.
- Air Pollution: Increased vehicular traffic, industrial emissions, and construction activities contribute to air pollution, impacting human health and the environment.
- Altered Wind Patterns: Tall buildings obstruct wind flow, creating localized wind tunnels and altering microclimates.
4. Loss of Biodiversity
- Habitat Fragmentation: Urban sprawl fragments natural habitats, isolating populations and reducing biodiversity.
- Loss of Green Spaces: Parks, gardens, and other green spaces are often sacrificed for construction, reducing habitat availability for plants and animals.
- Introduction of Invasive Species: Urban areas often serve as entry points for invasive species, which can outcompete native flora and fauna.
Examples of Indian Cities
Mumbai: Extensive reclamation of land from the sea has altered the coastal ecosystem and increased vulnerability to sea-level rise. The city also suffers from severe air and water pollution.
Delhi: Rapid urbanization and industrialization have led to significant air pollution, groundwater depletion, and loss of green cover. The Yamuna River is heavily polluted due to untreated sewage and industrial effluents.
Bangalore: Once known as the ‘Garden City’, Bangalore has experienced rapid, unplanned growth, leading to the loss of lakes, wetlands, and green spaces. This has exacerbated flooding and water scarcity.
| City | Key Biophysical Change | Contributing Factor |
|---|---|---|
| Mumbai | Coastal Ecosystem Alteration | Land Reclamation |
| Delhi | Air Pollution & Groundwater Depletion | Industrialization & Vehicle Emissions |
| Bangalore | Loss of Lakes & Wetlands | Unplanned Urban Growth |
Conclusion
The urban built environment in Indian cities undeniably creates significant changes in the biophysical character of the landscape. These alterations have far-reaching consequences for environmental sustainability and human well-being. Addressing these challenges requires a paradigm shift towards sustainable urban planning, incorporating green infrastructure, promoting public transportation, and implementing stricter environmental regulations. Prioritizing ecological considerations alongside economic development is crucial for creating livable and resilient cities for the future.
Answer Length
This is a comprehensive model answer for learning purposes and may exceed the word limit. In the exam, always adhere to the prescribed word count.