IGCSE Geography / River environments

Why rivers flood

Edexcel International GCSE Geography (4GE1), chapter 1: River environments, specification point 1.3c, 1.S5. Part of the full course.

Read the revision notes · IGCSE Geography past papers

Rivers flood when more water reaches a channel than it can hold, so it spills over its banks. Natural causes and human changes can make water reach rivers quickly and raise discharge.

More lessons in River environments

• The hydrological cycle: a closed system and its stores
• Transfers in the hydrological cycle
• Drainage basins and their features
• River regimes and what controls them
• Storm hydrographs
• How rivers erode
• Weathering and mass movement in river valleys
• How rivers carry and drop their load
• Long profile and cross profiles
• How a river changes downstream
• V-shaped valleys, interlocking spurs and waterfalls
• Meanders and oxbow lakes
• Flood plains and levees
• Case study: the River Tay from source to mouth
• Water: uses, rising demand and supply
• Water quality and pollution
• Storing and supplying clean water
• Case study: river management in Spain
• Case study: river management in China
• Case study: managing the Blue Nile in Ethiopia
• Predicting and preventing river floods
• River fieldwork: collecting the data
• River fieldwork: results, conclusions and evaluation