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Daily-current-affairs / 26 Oct 2023

Navigating Flood-Prone Urban Expansion: Strategies and Solutions : Daily News Analysis

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Date : 27/10/2023

RelevanceGS Paper 3 – Disaster Management

Keywords - World Bank, Water-Sensitive Urban Design, flood Zones, Rain Gardens

Context

A recent research conducted by the World Bank emphasizes the swift and ongoing growth of cities into regions prone to flooding.

World Bank Study Findings:

The recent World Bank study reveals a concerning trend: urban areas in India are rapidly expanding into flood-prone regions, doubling in size since 1985. This expansion poses a significant risk, leading to heightened instances of flooding and subsequent life and livelihood losses.

Illustrative Cases:

In Libya, which suffered severe flooding in September 2023, settlements in the worst flood zones increased by 83%. Similarly, Pakistan faced catastrophic floods in both 2022 and 2023, witnessing an 89% rise in settlements within vulnerable areas.

The study emphasizes that middle-income countries, including India, are witnessing a surge in urban settlements within flood-prone zones. Urgent action is required to integrate flood-related risks into urban planning strategies. Additionally, there is a critical need to enhance the flood resilience of low-income housing and implement improved storm-water management measures.

Factors Driving Human Settlements in Flood Zones:

  • Rural to Urban Migration: As countries experience economic growth, urbanization near waterways intensifies, leading to settlements in flood-prone areas. For instance, Dar es Salaam in Tanzania transformed from a fishing village into a city with over seven million residents within a short span.
  • Economic Constraints: Low-income populations are often compelled to reside in flood-prone zones due to affordability challenges in housing options.
  • Lack of Regulatory Oversight: Inadequate enforcement of land-use planning and zoning regulations results in unchecked settlements in flood-prone regions, lacking necessary safeguards.
  • Cultural and Historical Influences: Deep cultural or historical ties to flood-prone areas can influence decisions to settle or remain in these regions.
  • Tourism and Recreation: Despite their vulnerability to flooding, coastal and riverfront areas attract tourists and recreation enthusiasts, leading to human settlements.

Recommended Strategies:

Enforce Strict Land Use Policies: Implement regulations that prohibit or limit new constructions in high-risk flood zones, designating them as 'no-build' areas.

Invest in Infrastructure: Allocate resources for resilient infrastructure, encompassing flood defenses, early warning systems, and accurate floodplain mapping. Embrace innovative solutions like the 'Sponge Cities' concept, integrating permeable surfaces, canals, ponds, and wetland restoration to enhance water absorption and flood resilience.

A “sponge city” employs nature-based methods to enhance water absorption, drainage, and flood resilience.

Government Support and Relocation Aid: Offer financial incentives to encourage residents to relocate from flood-prone areas. Strengthen emergency response systems and preparedness measures.

Promote Public Awareness: Launch campaigns to educate the public about the risks associated with living in flood-prone zones. Encourage community-based education programs focusing on flood preparedness.

DO YOU KNOW?

What are Flash floods?

Flash floods are abrupt increases in water levels, often triggered by intense rainfall. These events are highly localized and brief, with a rapid surge that occurs within hours of the heavy rainfall. Their peak intensity is exceptionally high, and typically, there is a span of less than six hours between the onset of the rainfall and the flood's peak. The situation exacerbates when drainage systems are clogged or when encroachments impede the natural flow of water.

Causes of Flash Floods:

Flash floods can be instigated by intense rainfall accompanying severe weather phenomena like thunderstorms, hurricanes, tropical storms, or the rapid melting of ice or snow over ice sheets or snowfields. Dam or levee breaks and mudslides (debris flow) are also potential causes of flash floods.

Noteworthy Initiatives:

  1. Stormwater Disposal System (BRIMSTOWAD - Mumbai): Following the 2005 deluge, Mumbai initiated the Brihanmumbai Storm Water Disposal System (BRIMSTOWAD) to modernize the city's antiquated stormwater drainage system.
  2. Water-Sensitive Urban Design (WSUD - Australia): Water-Sensitive Urban Design in Australia reimagines urban stormwater runoff and wastewater as valuable resources rather than nuisances or liabilities.
  3. Bioswales or ‘Rain Gardens’ (New York): In New York, bioswales, also known as 'Rain Gardens,' are landscape features designed to capture polluted stormwater runoff, allowing it to seep into the ground and naturally filter out contaminants.

Conclusion:

Incorporating public open spaces as storm management infrastructure within urban areas is crucial. This integration can facilitate the transformation of cities into water-sensitive environments. By strategically designing these spaces to manage stormwater, cities can enhance their resilience to flooding, mitigate environmental risks, and create more sustainable urban landscapes that benefit both residents and the ecosystem.

Probable Question for UPSC Mains Exam

  1. Discuss the factors driving human settlements in flood-prone zones as highlighted in the World Bank study. How can these factors be effectively addressed through policy interventions to mitigate the risks associated with urban expansion into vulnerable regions? (10 marks, 150 words)
  2. Analyze the role of innovative initiatives such as bioswales, stormwater disposal systems, and water-sensitive urban design in managing urban flooding. Elaborate on their significance in transforming cities into water-sensitive environments and suggest ways to implement similar strategies in other urban centers. (15 marks, 250 words)

Source – The Hindu