What are 2 physical causes of flooding?
Physical causes of flooding:
- heavy rainfall.
- long periods of rain.
- snowmelt.
- steep slopes.
- impermeable rock (doesn’t allow water through)
- very wet, saturated soils.
- compacted or dry soil.
What are the physical impacts of flooding?
Loss of life: Floods can cause death and injury. People can get trapped in their houses by the quick rising waters. Pollution: Floods will wash chemicals and sewage into the water. The contaminated water will spread quickly over an area – causing public health issues and killing fish.
Why is Boscastle at risk of flooding?
Boscastle is located in a steep sided valley called the Valency Valley, where the river Valency flows down from Marshgate and onto the Boscastle harbour. The water quite easily runs into the river and increases the risk of flash flooding.
What are the major causes of floods?
Causes of Floods
- Massive Rainfall. Drainage systems and the effective infrastructure design aid during heavy rains.
- Overflowing of the Rivers.
- Collapsed Dams.
- Snowmelt.
- Deforestation.
- Climate change.
- Emission of Greenhouse Gases.
- Other Factors.
What are the physical and human causes of flooding?
Deforestation. Vegetation, including trees, intercept rainfall, slowing its movement. When vegetation is removed, infiltration and interception reduce and surface run-off increases. This leads to a greater risk of flooding as more water reaches the river channel.
What factors and physical causes contribute to a flood?
Why do floods occur?
- volume, spatial distribution, intensity and duration of rainfall over a catchment.
- the capacity of the watercourse or stream network to carry runoff.
- catchment and weather conditions before rainfall.
- ground cover.
- topography.
- tidal influences.
How does deforestation cause flooding?
When deforestation takes place, the top layer of soil can be dislodged – this is also known as soil erosion. When the top layer of soil is unstable, it is unable to retain any of the water that falls on it, resulting in increased surface run-off, which, in turn, increases the risk of flooding.
What are the causes and effects of floods?
Storm surge and tsunamis also cause flooding. Storm surges from hurricanes and other tropical systems can cause sea levels to rise and cover normally dry coastal areas in several feet of water. Tsunamis on the other hand are giant waves caused by earthquakes or underwater volcanic eruptions.
How is Banbury affected by flooding?
Banbury has suffered persistent damage from flooding due to the incapacity of the River Cherwell to convey excess surface run- off. The Environment Agency’s design concept proposed that flow control structures should throttle the river flows to 38m3/s and impound the additional floodwater in the reservoir.
What causes flooding in the UK?
Flooding is normally caused by natural weather events such as: heavy rainfall and thunderstorms over a short period. prolonged, extensive rainfall. high tide combined with stormy conditions.
What are human activities that cause flooding?
The drainage channels then overtop their natural or artificial banks and water enters the surrounding lands to cause flooding. Also human activities, which damage the environment, for example, sand mining, deforestation and poor garbage disposal, increase the risk of flooding.
What was the impact of the Boscastle flood?
A large quantity of water arrived within a short space of time causing the rivers to overflow. The flooding coincided with a high tide, making the impact much worse. Rain for 12 out of 14 days in August. Many trees had been cut down for farming.
How is the Environment Agency helping Boscastle?
The Environment Agency has carried a major project to increase flood defences in Boscastle, with the aim of preventing a similar flood happening again. We are investing in new ways of predicting heavy rainfall events on a small scale to produce better warnings.
Why is it important to know about Boscastle?
It is important to understand what causes flooding and what the effects can be. Flood prevention processes help to reduce damage and protect people in the event of a flood. Flooding can cause problems in both developed and developing countries. Boscastle is a small coastal settlement in the south west of England.
How much did the north Cornwall flood cost?
· Damage to buildings and services cost North Cornwall District Council up to £2 million. (North Cornwall District Council, 2004). · A dramatic decrease in tourist numbers immediately after the flood led to the town being described by business leaders as a ‘tourist ghost town’ (BBC, 2004b).
https://www.youtube.com/watch?v=P2QW9rsp570