Rivers & Coasts - Rivers Flashcards
What are the environmental factors that affect how bad a flood can be?
Slopes
Impermeable rock
Snow melt
Low lying areas
Deposit of silt (if the river has more silt there is less space for the water)
Number of smaller rivers going into the big river
Saturated land
What are the social factors that affect how bad a flood can be?
Global warming - rising sea levels
Deforestation
Over grazing (farming uses soil - less soil for the water to soak into)
Urbanisation
What are some flood management methods?
Dams
Widen/deepen/straighten the river
Planting trees
Pumping stations
Building up embankments/new flood walls
Restricting building on floodplains
Monitoring/warning systems
What are dams/reservoirs and what are the advantages/disadvantages?
Huge walls built across rivers, reservoirs are artificial lakes formed behind the dam
Advantages - reduce the risk of flooding as they store water and release it slowly, the water can be used for drinking water and hydroelectric power are also attractive
Disadvantages - Expensive to build, creating a reservoir can flood existing places, eroded material is deposited in the reservoir and not along the rivers natural course, making farmland less fertile
What is channel straightening and what are the advantages/disadvantages?
Where the rivers course is straightened
Advantages - reduces risk of flooding
Disadvantages - flooding may happen downstream as water is carried there faster
What are man made leeves and what are the advantages/disadvantages?
Man made embankments along both sides of the river
Advantages - the river can hold more water, reduces flooding also cheap
Disadvantages - if they break it can cause catastrophic flooding
What is flood warnings and what are the advantages/disadvantages?
People warned about floods through TV/radio ect
Advantages - impact of flooding is reduced
Disadvantages - warnings don’t stop floods from happening, people may not have access to the warnings
What is preparation and what are the advantages/disadvantages?
Buildings modified to reduce amount of damage of flooding, people plan
Advantages - impact of flooding is reduced
Disadvantages - doesn’t stop them from happening or guarantee safety, is expensive to modify buildings
What is flood plain zoning and what are the advantages/disadvantages?
Restrictions to prevent building on parts of the flood plain
Advantages - risk of flooding is reduced as impermeable surfaces aren’t created, impacts of flooding are reduced as there aren’t any buildings/people nearby
Disadvantages - there may not be any other space to build
