UPSC MainsGENERAL-STUDIES-PAPER-III202415 Marks250 Words
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Q18.

Urban Flooding: Causes, Cases & Policies

Flooding in urban areas is an emerging climate-induced disaster. Discuss the causes of this disaster. Mention the features of two such major floods in the last two decades in India. Describe the policies and frameworks in India that aim at tackling such floods.

How to Approach

This question requires a multi-faceted answer. First, define urban flooding and its causes, emphasizing the climate change link. Then, detail two major floods in India in the last two decades, highlighting their impacts. Finally, discuss relevant policies and frameworks. Structure the answer into an introduction, a body with sections for causes, case studies, and policies, and a conclusion. Focus on providing specific examples and data wherever possible.

Model Answer

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Introduction

Urban flooding, distinct from riverine floods, is the inundation of built-up areas caused by intense rainfall, inadequate drainage, and other factors. It’s an increasingly prevalent climate-induced disaster, exacerbated by rapid urbanization and changing weather patterns. India, with its burgeoning urban population and vulnerability to monsoon rains, faces a significant threat. Recent events like the Chennai floods (2015) and the Mumbai floods (2023) underscore the growing frequency and intensity of urban flooding, demanding a comprehensive understanding of its causes and effective mitigation strategies. This answer will explore these aspects, along with the existing policy frameworks.

Causes of Urban Flooding

Urban flooding is a complex phenomenon with interconnected causes:

  • Climate Change: Increased frequency and intensity of extreme rainfall events due to climate change are a primary driver.
  • Rapid & Unplanned Urbanization: Expansion of concrete jungles reduces permeable surfaces, hindering water infiltration and increasing runoff.
  • Inadequate Drainage Systems: Many cities have outdated or insufficient drainage infrastructure, unable to cope with increased rainfall.
  • Encroachment of Natural Waterways: Construction on riverbeds, wetlands, and natural drainage channels obstructs the flow of water.
  • Poor Waste Management: Blocked drains due to plastic and other waste exacerbate flooding.
  • Deforestation: Loss of vegetation reduces the land’s capacity to absorb rainwater.
  • Local Topography & Geomorphology: Low-lying areas and flat terrains are naturally more prone to flooding.

Major Floods in India (Last Two Decades)

1. Chennai Floods (2015)

Chennai experienced unprecedented rainfall in November-December 2015, receiving over 1200mm of rainfall in a month. This led to widespread flooding, crippling the city for days. Key factors included:

  • Failure of the Chembarambakkam reservoir management.
  • Encroachment of waterways like the Adyar River.
  • Inadequate drainage infrastructure.
  • The impact was devastating, causing over 280 deaths and economic losses estimated at ₹20,000 crore (as per initial estimates).

2. Mumbai Floods (2023)

Mumbai witnessed heavy rainfall in July 2023, resulting in significant flooding in several parts of the city. While not as severe as the 2005 floods, the 2023 event highlighted persistent vulnerabilities:

  • Intense rainfall exceeding the capacity of the city’s drainage system.
  • Obstruction of stormwater drains due to plastic and debris.
  • High tide coinciding with heavy rainfall, hindering drainage.
  • Disrupted transportation and economic activities, with estimated losses of several crores.

Policies and Frameworks for Tackling Urban Floods

India has several policies and frameworks aimed at mitigating urban flooding:

  • National Disaster Management Authority (NDMA): Provides guidelines for urban flood management, including early warning systems and preparedness measures.
  • National Mission for Sustainable Habitat (NMSH): Under the National Action Plan on Climate Change (NAPCC), focuses on promoting sustainable urban development and climate-resilient infrastructure.
  • Atal Mission for Rejuvenation and Urban Transformation (AMRUT): Aims to improve basic urban infrastructure, including drainage systems.
  • Smart Cities Mission: Promotes the use of technology and data analytics for better urban planning and flood management.
  • National Urban Housing Fund (NUHF): Supports the development of affordable housing, which can incorporate flood-resilient designs.
  • Flood Plain Zoning Act (FPZA): Though not uniformly implemented across states, aims to regulate construction in flood-prone areas.
  • State-level Disaster Management Plans: Each state has its own disaster management plan, which includes provisions for urban flood management.

However, effective implementation and inter-departmental coordination remain significant challenges.

Conclusion

Urban flooding is a growing threat to India’s cities, driven by climate change and exacerbated by unplanned urbanization. While India has a range of policies and frameworks to address this challenge, their effective implementation requires a holistic approach encompassing improved drainage infrastructure, stricter enforcement of regulations, community participation, and a focus on nature-based solutions. Investing in resilient infrastructure and proactive disaster preparedness is crucial to minimize the devastating impacts of urban floods and ensure the safety and sustainability of our cities.

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

Permeable Surface
A surface that allows water to infiltrate into the ground, such as soil, sand, or porous pavement. Reducing permeable surfaces contributes to increased runoff and urban flooding.
Stormwater Drain
A system of pipes and channels designed to collect and convey rainwater runoff from urban areas, preventing flooding.

Key Statistics

According to a 2021 report by the World Bank, India is among the most vulnerable countries to climate change, with urban areas particularly at risk from increased flooding.

Source: World Bank Climate Change Knowledge Portal (2021)

A 2023 study by the Centre for Science and Environment (CSE) found that over 40% of India’s urban population is vulnerable to flooding.

Source: Centre for Science and Environment (CSE), 2023

Examples

Sponge City Concept

The "Sponge City" concept, pioneered in China, involves creating urban areas that absorb and reuse rainwater, reducing runoff and mitigating flooding. This includes green roofs, permeable pavements, and restored wetlands.

Frequently Asked Questions

What is the role of early warning systems in urban flood management?

Early warning systems provide timely information about impending floods, allowing residents to evacuate and authorities to take preparedness measures, thereby reducing loss of life and property damage.

Topics Covered

EnvironmentGovernanceDisaster ManagementClimate ChangeUrban PlanningDisaster MitigationInfrastructure Development