Flood risk

• What is the recurrence interval in relation to floods?

  Average time between extreme flood events
• Why are floods considered more common hazards?

  Due to the number of people on floodplains
• How do urban areas cope with regular floods?

  They can manage annual flood occurrences
• What is a challenge for few places regarding floods?

  High magnitude, low frequency events
• What are the main climatological causes of floods?

  • Rain
  • Ice melt
  • Snow melt
• What are the part-climatological causes of floods?

  • Estuarine interactions
  • Coastal storm surges
• What are other causes of floods besides climatological factors?

  • Earthquake
  • Landslide
  • Dam failure
• How does urbanization contribute to flood risk?

  Increases rapid discharge due to impermeable surfaces
• What impact do floodplain developments have?

  They increase the risk of flood damage
• What human-made structures can contribute to flooding?

  Bridges, dams, and obstructions
• How does change in vegetation cover affect flooding?

  It can increase flood risk
• What role do river engineering works play in flooding?

  They can increase flood risk
• What is a significant human-induced factor contributing to floods?

  Climate change
• How has flood forecasting changed since the 80s and 90s?

  It has become more accurate
• What is a limitation of flood warning times in homes?

  50% have less than 6 hours warning
• How does flood forecasting differ in LICs compared to other regions?

  It is much less effective in LICs
• What is an exception for flood forecasting in LICs?

  Bangladesh has effective forecasting
• Why does Bangladesh have better flood warning times?

  Most floods originate from the Himalayas
• How much warning time do floods in Bangladesh typically provide?

  Around 72 hours warning time