Flood Prediction & Flood Prevention

Flood Prediction

1. What is a recurrence interval?

   • The average time between floods of a certain size.

2. What is a 100-year flood?

   • A flood expected to occur once every 100 years, on average.

3. How can floods be predicted using graphs?

   • By plotting flood magnitude against recurrence interval and using a best-fit line.

4. What is another method for predicting floods?

   • Examining historical flood records.

5. What do flood risk maps show?

   • Areas likely to flood, categorized by risk.

6. What does a severe flood risk category mean?

   • Floods with a recurrence interval of 1-75 years.

7. What does a moderate flood risk category mean?

   • Floods with a recurrence interval of 76-200 years.

8. Where are the areas most at risk of flooding?

   • Low-lying floodplains, small basins prone to flash floods, unsafe dams, and low-lying inland shorelines.

Flood Prevention

9. How does forecasting and warning work for floods?

   • Through weather satellites, emergency plans, and river discharge gauges.

10. What role do computer models play in flood forecasting?

    • They compare new data with historical trends to predict floods.

11. What is loss sharing in flood prevention?

    • Using disaster aid and insurance to help share the costs of flood damage.

12. What does hard engineering involve?

    • Works that counter natural processes, such as dams, levees, and channel straightening.

13. What is the drawback of hard engineering?

    • While it solves local flood problems, it can increase risks upstream or downstream.

14. What is hazard-resistant design for buildings?

    • Modifying structures with sandbags, sealing doors/windows, and moving valuables off lower floors to reduce damage.

15. How are flood gates used for flood prevention?

    • They are installed on individual buildings, like in Yarm on the River Tees.

16. What is land use zoning in flood management?

    • Avoiding construction on flood-prone areas and allowing natural flooding on floodplains.

17. What is soft engineering for flood prevention?

    • Working with natural processes, such as afforestation, contour ploughing, and flood diversion.

18. What does flood abatement do?

    • It reduces the amount of runoff through techniques like afforestation and sediment removal.

19. What is the goal of flood diversion?

    • To designate areas where flooding can occur safely, rather than on built-up areas.

20. How is land used on floodplains to reduce flood risk?

    • Areas closest to the river should have protected wetlands, rough grazing, and parks, with critical buildings furthest away.