Living with the Deluge

Why in News?

• The floods in north-western India and Delhi over the last week has left citizens stranded, flooded homes and the emergency evacuation of people is being carried out.
• This is now a recurrent, lived monsoon experience for many of our cities from Mumbai and Chennai to Bengaluru.

 

Global Warming: Reason Behind Frequent Floods in Cities in Recent Years

• As global warming increases and local warming in our cities goes well beyond the 2 Degree- Celsius, the intensity of climatic-impact drivers like too much or too little rain and heat will increase, as will the frequency and intensity of extreme weather.
• As per IPCC, and the Indian Institute of Tropical Meteorology (IITM) this may not grow incrementally each year. 
• It could grow exponentially, much faster than our current governance, planning and infrastructure systems are able to adapt to. 

 

Why Climate Impacts and Risks (e.g., Flooding) are Felt Intensely in Cities

• Extremely Poor Basic Infrastructure
  • Our cities concentrate one-third of our people and two-third of our economic output in increasingly dense built-up areas, with poor water, sanitation, drainage, and wastewater infrastructure that struggle to even deliver everyday basic services.
• Irrational Land use and Planning Systems
  • This only worsens existing challenges and amplify the vulnerability of tens of millions who are forced to live in informal settlements and slums.
  • Cities in sensitive regions along the coast, rivers and hills face even worse impacts, due to higher exposure and locational vulnerability.

 

Existing Emergency Response Measures

• Because of the above complex interacting factors, traditional siloed responses to the climate crisis are doomed to fail.
• Yet various cities across the country have successfully implemented several common-sense climate adaptation and flood response measures.

 

Measures Cities Must Employ to Reduce Loss of Life and Economic Activity

• Monsoon Audit Mechanism
  • Most urban civic bodies conduct a monsoon audit ahead of the season. This is to ensure that storm water drains, tanks and lakes exist and work, and they are not choked by construction debris, silt, garbage or blocked by encroachments.
  • It is a complex task that needs planning all through the year and adequate financial and human resources, which are rarely a priority.
  • If done well, this can reduce the impact of flooding, along with helping recharge groundwater and surface storage, when the rain arrives.
• Ensuring Working Drainage in Every City
  • The medium-term solution is the integration of drainage, water supply and wastewater systems.
  • This will store the intense rain that may come over a short period as well as treat and recycle wastewater to ensure safe water and sanitation through the rest of the year. This will enable better services and limit waterborne diseases.
  • It needs to ensure that our drainage systems have enough capacityto take the greater intensity of rain that will come with a changing climate.
  • Therefore, there is need to improve basic infrastructure in large cities, through schemes like AMRUT but the pace is far behind the accelerating changes in rainfall and urban expansion.
• Improving Roads
  • The expansion of our urban areas faster than planned drainage systems means that many roads effectively become stormwater drains.
  • Every time a tar road is repaired. As tar is laid on top without milling down the existing road, road level rises above surrounding areas.
  • To reduce local flooding, we need to improve the way city roads are built and repaired.
• Effective Co-ordination among Civic Departments and Urban Planners
  • The situation gets worse when most flyovers, underpasses and sometimes metro lines built to address traffic, land up disrupting existing drainage, leading ironically to massive traffic bottlenecks post-flooding.
  • This needs to be addressed with effective infrastructure planning and coordination among all concerned agencies, as has been demonstrated in many cities.
• A Proper Balance Between Green and Grey Infrastructure
  • As our cities expand to become impervious concrete jungles, there is less place for water to percolate and flow.
  • Conserving and protecting urban forests, wetlands, rivers, and lakes are critical to addressing climate change-induced flooding, water scarcity and heat waves and improving liveability.
  • For example, China is trying to transform 30 of its megacities into “sponge cities” that use green roofs to slow down run-off into drains, urban forests to enable percolation, groundwater recharge and wetlands to absorb and reuse two-thirds of their water.
  • In India, for over a century, East Kolkata’s wetlands have been an effective flood defence mechanism that help treat a large share of the city’s sewage, produce half of the city’s fresh vegetables, and provide livelihoods to one lakh people.
  • Practical nature-based blue-green-grey infrastructure such as these hold the key to climate adaptation for many Indian cities.
• Improving Early Warning Services
  • India has done well to improve its forecasting, early warning, and evacuation systems in many large cities.
  • This has to be extended to most places that are at risk along with strengthening critical cell phone, power and water supply services so that they are resilient and can recover rapidly from extreme events.

 

Challenges in Reducing Flood Vulnerability

• India has the technological capacity to map all of its cities and towns, using high-resolution satellite and local topographical data to identify areas most prone to flooding.
• The challenge is to address the vulnerability of millions of people, who live along river banks, low-lying areas and unstable slopes, whose everyday lives are dislocated during extreme events.
• We have become much better at evacuation and protecting people’s lives but have a long way to go in enabling real community-based resilience.

 

Way Forward

• The most effective way to protect and prepare our cities to climate related calamities is to ensure that all urban residents have access to basic environmental services: Water, sanitation, drainage, and solid waste management.
• We need to reduce our collective vulnerability, improve public health, and re-imagine our cities to have more forests, parks, wetlands, and lakes that are not disturbed by irrational and often illegal changes in land use and poorly regulated real estate interests.

 

Conclusion

• It is time to accept that we live in a warming world, in which climate change is a harsh reality that all of us, poor or rich, need to adapt to.
• And we need to protect and prepare our cities for future flooding, drought and heat waves that will arrive at our doorsteps with climate change. 

 

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Q1) How do cities and climate change impact each other?

Climate change is a global phenomenon that largely impacts urban life. Rising global temperatures causes sea levels to rise, increases the number of extreme weather events such as floods, droughts and storms, and increases the spread of tropical diseases. All these have costly impacts on cities' basic services, infrastructure, housing, human livelihoods and health. At the same time, cities are a key contributor to climate change, as urban activities are major sources of greenhouse gas emissions. Estimates suggest that cities are responsible for 75 percent of global CO2 emissions, with transport and buildings being among the largest contributors.

 

Q2) What is the difference between Grey and Green infrastructure?

Green infrastructure refers to natural systems including forests, floodplains, wetlands and soils that provide additional benefits for human well-being, such as flood protection and climate regulation. Grey infrastructure refers to structures such as dams, seawalls, roads, pipes or water treatment plants.

 

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Source: The Indian Express