Floods Flashcards
What is a flood?
When there is too much water in one place. A river cannot contain the water in it, and the water spreads out over the riverbanks
What causes floods?
The main cause is heavy rain, but environmental factors and human activity can increase the effects of a flood
What can farmers do to prevent the impact of floods?
Practice contour ploughing (ploughing the land from side to side across a slope rather than from top to bottom”
How do fires and deforestation cause floods?
Soil erosion occurs and gets washed into the river. The eroded soil settles at the bottom of rivers and dams or blocks the path of water which raises the water level
How does human settlement contribute to flooding?
In cities and towns much of the surface consists of roofing, tar and concrete stop less water can soak into the soil, increasing flooding
What are tsunamis?
Huge waves caused by earthquakes under the sea
What is a storm surge?
Tropical cyclones, also called Harry Keynes and typhoons bring very strong winds and high rainfall
Name some negative effects of floods
Injury and loss of life Disease Displacement of people Damage to buildings and infrastructure Soil erosion and damage to fields
How do floods cause death?
People drown because of the speed and intensity of the rising water
People can also be hit by debris carried by water
Why do floods cause disease? And which diseases do they carry?
Cholera, dysentery and diarrhoea occur after floods as water pipelines, sewerage pipes and dams are destroyed. Although there was water everywhere, people do not have access to clean drinking water and so they are at high risk of contracting waterborne diseases
How do floods damaged infrastructure?
Floodwaters destroy roads and railway lines
Communication links do not work when telephone lines are damaged
Buildings and powerlines can be destroyed
Houses are damaged
Toxic materials such as paints, pesticides, petrol and diesel can end up in the rivers and in the ocean
Why are some communities at higher risk for floods than others?
Developed countries have effective warning systems
Underdeveloped countries do not have good roads to evacuate inhabitants
Underdeveloped countries have little money to provide flood relief
How can the risk of flood be reduced?
Town and city planners need to make sure wetlands are protected, as they absorb water
Stormwater drains must be built and kept free from debris
Residents should not be allowed to build houses in areas that are prone to flooding — next to rivers and in low lying areas
Houses should be built on higher ground
A good communication network should be set up to give early warning of flood
Furrows should be dug to force water away from homes
