Floods in UAE and Oman

GS-3 Mains : Disaster Managements 

Revision Notes 

Question : Examine the role of global warming and El Niño in contributing to the extreme rainfall events witnessed in the UAE and Oman. What are the implications of rising sea surface temperatures and changing circulation patterns on precipitation patterns in the Arabian Peninsula?

Context

• Recent storms in UAE and Oman were likely intensified by climate change, according to researchers.

About the Rainfall

• UAE experienced its heaviest rainfall on record in under 24 hours (equivalent to over a year and a half’s worth).
• The Arabian Peninsula experiences occasional intense rain in April/May from mesoscale convective systems (multiple thunderstorms acting as a single system).

Reasons for Extreme Rainfall

• Global Warming:
  • A team of researchers found climate change made extreme rainfall events 10-40% more intense.
  • A warmer atmosphere holds more moisture (8.4% more with a 1.2-degree temperature increase), leading to heavier rain.
  • Changing circulation patterns from global warming also increase rainfall intensity.
• El Niño:
  • The rainfall occurred after months of hotter-than-average sea surface temperatures partly caused by El Niño (warm water rising in parts of the Pacific Ocean).
  • Higher ocean temperatures add more moisture to the atmosphere, increasing the likelihood of heavy rainfall.
• Infrastructure and Soil:
  • Cities lacked adequate storm management.
  • Very dry soil in the region struggles to absorb excess water, worsening the impact.

What are Floods?

• Floods are the most frequent natural disaster, submerging land that is usually dry.

Types of Floods

• Flash floods: Caused by rapid, excessive rainfall, raising water heights quickly.
• River floods: Caused by consistent rain or snowmelt exceeding a river’s capacity.
• Coastal floods: Caused by storm surges associated with tropical cyclones and tsunamis.
• Urban floods: Caused by land development replacing permeable soil with impermeable surfaces.

Causes of Floods

• Natural Causes:
  • Prolonged rainfall: Saturated soil cannot absorb water, leading to surface runoff and flooding.
  • Intense/Heavy rainfall: Raindrops hit the ground with force, bouncing off instead of infiltrating the soil, increasing surface runoff.
  • Relief: Water flows quickly from mountains/hills to low-lying areas, making them more flood-prone.
• Anthropogenic Causes:
  • Deforestation: Lack of vegetation encourages surface runoff instead of infiltration.
  • Poor land-use practices: Unsustainable practices degrade soil, reducing its ability to absorb water.
  • Urbanization: Permeable soil is replaced with impervious surfaces (concrete/pitch) that prevent water infiltration.
  • Improper waste disposal: Clogged drains due to improper waste disposal can worsen flooding.
  • Quarrying: Removal of vegetation for construction materials increases surface runoff.
  • Collapsed Dams: Dam collapse releases large amounts of water downstream, causing floods.
  • Climate Change: Uncontrolled human activities contribute to climate changes that increase flooding.

Implications of Floods

• Drowning: Accounts for 75% of flood deaths, with higher risks in low- and middle-income countries.
• Health Impacts:
  • Water-borne diseases (cholera, typhoid, malaria)
  • Injuries from evacuation and cleanup
  • Chemical hazards from contaminated floodwater
  • Mental health effects from emergencies
  • Disrupted health systems
• Damaged Infrastructure: Disruptions to food, water supplies, and safe shelter.
• Economic Losses: Significant costs to individuals and the state.

Prevention of Floods

• Drainage Improvement: Ensure proper drainage systems in new developments.
• Flood Water Diversion: Divert floodwater into natural or artificial channels.
• Catchment Area Treatment/Afforestation: Increase vegetative cover through afforestation and soil conservation to reduce flood peaks.
• Anti-erosion Works: Implement measures to minimize bank erosion and control river currents.
• Inspection and Maintenance: Regularly inspect, maintain, and rehabilitate flood control structures.