Understanding the Rising Rainfall in Indian Cities

What Is Happening?

Over the past four decades, several of India’s major cities have experienced a notable increase in rainfall and moisture levels. A study conducted by the University of Bristol and Cardiff University, commissioned by WaterAid, revealed that 11 Indian cities, including Mumbai, Delhi, Bengaluru, and Kolkata, have witnessed a rise in wet conditions from 1982 to 2023. Notably, cities like Surat have ranked among the highest globally for this trend.

Why Is This Happening?

• Climate Change: Global warming is altering rainfall patterns, resulting in more intense and frequent downpours.
• Urbanization: Expanding cities, with their concrete infrastructure, hinder natural drainage and lead to increased water accumulation.
• Evapotranspiration Changes: The rise in atmospheric moisture due to warming significantly impacts the water cycle.
• Infrastructure Gaps: Many cities lack adequate drainage systems, rendering them increasingly vulnerable to flooding.

What Can Be Done?

• Sponge Cities Approach:
  • This innovative concept focuses on designing urban areas to effectively absorb, store, and release rainwater.
  • Key Features:
    • Green roofs to capture rainwater.
    • Permeable pavements that facilitate water absorption.
    • Urban wetlands and water bodies serving as natural reservoirs.
• Improved Drainage Systems:
  • Enhancing and maintaining drainage networks to manage excess rainfall effectively.
  • Implementing advanced stormwater management systems.
• Rainwater Harvesting:
  • Collecting and reusing rainwater for non-potable purposes to decrease surface runoff.
• Afforestation and Green Spaces:
  • Expanding tree cover and parks to naturally absorb rainwater.
  • Restoring lakes and ponds to better manage excessive rainfall.
• Climate-Resilient Urban Planning:
  • Designing urban infrastructures that are resistant to flooding.
  • Implementing zoning laws to restrict construction in flood-prone areas.

Conclusion

The increasing wetness in Indian cities brings significant flooding risks, making sustainable urban planning essential. Adopting the sponge city model, enhancing drainage systems, and promoting green cover can help cities effectively adapt to the evolving climate conditions.

Frequently Asked Questions (FAQs)

Q1. What are sponge cities and how do they work?
Answer: Sponge cities are urban areas designed to absorb, store, and release rainwater efficiently. They incorporate features like green roofs and permeable pavements to manage excess rainfall and reduce flooding risks.

Q2. How does climate change affect rainfall patterns in India?
Answer: Climate change leads to global warming, which alters rainfall patterns, resulting in more intense and frequent downpours in urban areas, increasing the risk of flooding.

Q3. What role does urbanization play in flooding?
Answer: Urbanization contributes to flooding by creating concrete infrastructure that reduces natural drainage, leading to increased water accumulation during heavy rains.

Q4. What are effective strategies for rainwater harvesting?
Answer: Effective rainwater harvesting strategies include capturing rainwater from roofs and surfaces for reuse in irrigation and non-potable applications, thereby reducing surface runoff and conserving water.

Q5. Why is improved drainage crucial for Indian cities?
Answer: Improved drainage systems are essential for managing excess rainfall, preventing waterlogging, and minimizing the risk of urban flooding, especially in rapidly growing cities.

UPSC Practice MCQs

Question 1: What is a key feature of sponge cities?
A) Concrete pavements
B) Green roofs
C) High-rise buildings
D) Industrial zones
Correct Answer: B

Question 2: Which factor contributes most to urban flooding in Indian cities?
A) Climate change
B) Agricultural practices
C) Rural migration
D) Deforestation
Correct Answer: A

Question 3: What is the primary goal of rainwater harvesting?
A) To reduce pollution
B) To generate electricity
C) To capture and reuse rainwater
D) To increase biodiversity
Correct Answer: C

Question 4: How does urbanization impact drainage systems?
A) It improves them
B) It has no effect
C) It complicates natural drainage
D) It reduces water demand
Correct Answer: C