Flooding (Copy)
6.3 Flooding – Cheat Sheet
Causes of Flooding
| Cause | Explanation | Example |
|---|---|---|
| Heavy Rainfall | Intense storms can overwhelm drainage and rivers | Monsoon floods in Bangladesh |
| Prolonged Rainfall | Continuous rain saturates soil, increasing run-off | UK floods, 2007 |
| Snowmelt | Rapid melting of snow/ice adds huge volumes to rivers | Himalayas → Ganges flood risk |
| Land Relief | Low-lying, flat floodplains prone to flooding | Mississippi Delta |
| Saturated Soil | Soil already waterlogged → no further infiltration | Amazon basin floods |
| Compacted Soil | From farming, grazing, or construction → reduces infiltration → more run-off | Urban flash floods |
| Deforestation | Fewer trees → less interception, more run-off | Nepal floods due to hillside clearance |
| Cultivation | Exposed soils increase erosion and sediment in rivers | Sahel region |
| Urbanisation | Concrete surfaces prevent infiltration, increase surface run-off | Flash floods in Karachi |
| Storm Surges | High winds push seawater inland during cyclones | Cyclone Nargis, Myanmar (2008) |
| Tsunamis | Seismic sea waves flood coastal areas | Indian Ocean tsunami, 2004 |
| Sea Level Rise | Climate change raises global sea levels → more coastal flooding | Maldives under threat |
Quick Pointers
- Flooding = combination of natural factors (rainfall, snowmelt, relief) + human activities (deforestation, urbanisation).
- Coastal floods often linked to storm surges, tsunamis, climate change.
- Impacts: loss of life, displacement, crop damage, economic losses.
Written and Compiled By Sir Hunain Zia, World Record Holder With 154 Total A Grades, 7 Distinctions and 11 World Records For Educate A Change O Level And IGCSE Environmental Management Full Scale Course