In GCSE Geography students will look at rivers. One aspect of this topic is flooding. This is one of two quizzes on flooding and it focusses in particular on the causes and the effects of floods.
Floods can have devastating effects. In 2014, across Europe the estimated cost of flood damage was around £3.2 billion. It’s thought that by 2050 the cost could have risen to £16 billion as more extreme weather conditions lead to more extreme and more frequent flooding. It is also estimated that the formerly once in a century extreme events could become annual occurances.
A river is normally seen as just being the channel that it flows through, but in reality the flood plain either side of the river, as well as the bogs, marshes and pools that flank the river channel, not forgetting the tributaries and distributaries, should all be considered an integral part of the river.
What does this more inclusive view of a river mean? Well, we need to accept that flooding is a natural part of any river cycle. The flood plains are carved by rivers and sculptured by the floods themselves.
What exactly are the causes of flooding? A huge range of factors influence how much time the water takes from reaching the ground to entering the river. These factors include the speed of drainage into parts of the river channel, and what is there to slow and prevent the water reaching the channels immediately. Studies show that some modern rivers can carry water from the land near their source to the estuary in a matter of hours, when before deforestation, channel straightening, drainage and changing land use it would have taken days. The faster the water reaches the channel after raining the higher the risk of flooding in high risk areas.
Try this quiz to see how much you have learned about the causes and the effects of floods.