UPSC MainsGEOLOGY-PAPER-II20235 Marks150 Words
Q18.

Discuss environmental impacts of urbanization and their mitigations with special reference to land and water.

How to Approach

This question requires a structured response outlining the environmental consequences of urbanization, specifically focusing on land and water resources, and then detailing mitigation strategies. The answer should demonstrate an understanding of the interconnectedness of these issues. A good approach would be to first define urbanization, then detail its impacts on land (soil erosion, loss of biodiversity, etc.) and water (pollution, depletion), followed by mitigation strategies for each. Examples and case studies will strengthen the answer.

Model Answer

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Introduction

Urbanization, the increasing concentration of population in urban areas, is a global phenomenon, particularly pronounced in developing countries like India. As per the UN, 56% of the world’s population lives in urban areas, projected to increase to 68% by 2050. This rapid growth places immense pressure on natural resources, leading to significant environmental impacts. Specifically, land and water resources are severely affected by urbanization through habitat loss, pollution, and altered hydrological cycles. Addressing these impacts is crucial for sustainable urban development and environmental protection.

Environmental Impacts of Urbanization on Land

Urbanization drastically alters land cover, leading to several environmental consequences:

  • Loss of Biodiversity: Conversion of natural habitats (forests, wetlands) into built-up areas results in habitat fragmentation and loss of species.
  • Soil Erosion & Degradation: Construction activities and removal of vegetation cover expose soil to erosion by wind and water. Impervious surfaces (roads, buildings) increase runoff, exacerbating erosion.
  • Land Degradation & Pollution: Improper waste disposal, industrial effluents, and agricultural runoff contaminate soil with heavy metals and other pollutants.
  • Urban Heat Island Effect: Concentration of concrete and asphalt absorbs and retains heat, leading to higher temperatures in urban areas compared to surrounding rural areas.
  • Altered Hydrological Cycle: Increased impervious surfaces reduce infiltration, leading to increased runoff and decreased groundwater recharge.

Environmental Impacts of Urbanization on Water

Urbanization significantly impacts water resources through:

  • Water Pollution: Discharge of untreated sewage, industrial wastewater, and agricultural runoff into water bodies contaminates them with pathogens, organic matter, and toxic chemicals.
  • Water Depletion: Increased water demand for domestic, industrial, and agricultural purposes leads to over-extraction of groundwater and surface water resources.
  • Increased Runoff & Flooding: Impervious surfaces increase runoff volume and velocity, leading to increased risk of urban flooding.
  • Changes in Water Quality: Altered stream morphology and increased sediment load affect water quality and aquatic ecosystems.
  • Saltwater Intrusion: Over-extraction of groundwater in coastal areas can lead to saltwater intrusion, contaminating freshwater aquifers.

Mitigation Strategies for Land-Related Impacts

  • Green Infrastructure: Implementing green roofs, urban forests, and permeable pavements to reduce runoff, mitigate the urban heat island effect, and enhance biodiversity.
  • Sustainable Land Use Planning: Adopting compact urban development patterns, promoting mixed-use zoning, and preserving green spaces.
  • Soil Conservation Measures: Implementing erosion control measures during construction, promoting soil remediation techniques, and encouraging organic farming practices.
  • Waste Management: Implementing integrated waste management systems, including waste reduction, reuse, recycling, and composting.
  • Brownfield Redevelopment: Rehabilitating contaminated sites (brownfields) for reuse, reducing the need for developing new land.

Mitigation Strategies for Water-Related Impacts

  • Wastewater Treatment: Investing in advanced wastewater treatment technologies to remove pollutants and enable water reuse.
  • Rainwater Harvesting: Promoting rainwater harvesting at household and community levels to augment water supply and reduce runoff.
  • Water Conservation: Implementing water-efficient technologies and promoting water conservation practices in domestic, industrial, and agricultural sectors.
  • Stormwater Management: Implementing sustainable stormwater management practices, such as detention basins, swales, and green infrastructure, to reduce runoff and flooding.
  • Groundwater Recharge: Implementing artificial groundwater recharge techniques to replenish groundwater aquifers.

The National Mission for Sustainable Habitat (NMSH), a part of the National Action Plan on Climate Change (NAPCC), aims to improve energy efficiency in urban areas and promote sustainable urban transport. Similarly, the Atal Mission for Rejuvenation and Urban Transformation (AMRUT) focuses on establishing basic services like water supply, sewerage, and stormwater drainage in 500 cities.

Conclusion

Urbanization presents significant environmental challenges to land and water resources. However, through proactive planning, sustainable infrastructure development, and effective mitigation strategies, these impacts can be minimized. A holistic approach integrating environmental considerations into urban planning and governance is essential for creating resilient and sustainable cities. Investing in green infrastructure, promoting water conservation, and adopting circular economy principles are crucial steps towards achieving a harmonious balance between urban development and environmental protection.

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.

Additional Resources

Key Definitions

Impervious Surface
A surface that does not allow water to penetrate into the soil, such as concrete, asphalt, and buildings.
Urban Heat Island Effect
The phenomenon where urban areas experience significantly warmer temperatures than surrounding rural areas due to human activities and modifications of land surfaces.

Key Statistics

India's urban population is projected to reach 600 million by 2031, representing approximately 40% of the total population.

Source: Census of India, 2011 & UN projections (knowledge cutoff 2023)

Approximately 75% of India’s surface water resources are polluted, largely due to domestic sewage and industrial effluents.

Source: Central Pollution Control Board (CPCB) Report, 2019 (knowledge cutoff 2023)

Examples

Singapore's Water Management

Singapore, facing water scarcity, has implemented a comprehensive water management strategy including rainwater harvesting, desalination, NEWater (recycled water), and water conservation measures.

Frequently Asked Questions

What is the role of urban planning in mitigating environmental impacts?

Effective urban planning can minimize environmental impacts by promoting compact development, preserving green spaces, integrating green infrastructure, and prioritizing sustainable transportation options.

Topics Covered

GeographyEnvironmentUrban PlanningEnvironmental PollutionSustainable Development