Deck 35- Flooding Flashcards
What are the four meteorological causes of flooding?
-Intense precipitation
-Prolonged heavy precipitation
-Seasonal monsoonal rainfall
-Snowmelt
What are three human causes of flooding?
-Urbanisation
-Deforestation
-Mismanagement of river channels
When did a convectional precipitation event lead to flooding in the UK?
10th September 2023, Newcastle (after the Great North Run)
What were the impacts of the flooding after the 2023 Great North Run?
- High temperatures throughout the day impacted 60,000 runners at the Great North Run
- Intense rainfall flooded South Shields and Bede Metro Stations causing the service to be suspended for 1 hour
- Thousands were left stranded at the end of the event leading to some participants walking up to 7 miles home
What was the name of the cyclone that caused flooding in Bangladesh and when did it occur?
Cyclone Bhola hit Bangladesh on the 8th November 1970
What were the impacts of Cyclone Bhola?
- Death of over 500,000 people and millions made homeless and displaced
- Spread of waterborne diseases and contamination of water supply
Why is flooding common in the Bay of Bengal area?
Tropical cyclones are common in the Bay of Benegal due to warm sea temperatures. The intense precipitation alongside storm surges (up to 10 metres) can flood large areas of lands
Give an example of a UK flooding event that was caused by prolonged rainfall.
The River Don flooding Sheffield on 15th June 2007
What were the impacts of the River Don (Sheffield) floods in 2007?
- On 15th June 2007, the city experienced one month’s rainfall in 2 days which totalled 91mm
- 2 people died, over 12,00 homes were flooded and 13,000 people have no power for two days
- £15 million of damages to businesses e.g. Clarkson Osborn, Sheffield Forgemasters International and Cadbury Trebor Bassett
- Meadow Hall shopping centre and the Hillsborough Football Stadium flooded under 6ft of water
Which country experiences severe monsoonal flood events?
Bangladesh- floods most years with catastrophic events in 1951, 1997, 1988, 1998, 2004, 2007, 2010, 2015, 2017 and 2022
What causes the seasonal monsoon events in South Asia?
South Asia experiences a seasonal change in wind direction that brings changes in amounts of precipitation i.e. wet season in the summer and a dry season in the winter
What are were impacts of the 2022 monsoon?
- Extreme flooding took place on 23rd May 2022 in both India and Bangladesh
- A total of 318 people died (177 in India and 141 in Bangladesh)
- In India over 4,000 villages were damaged and 113,00 hectares of crops destroyed
- In Bangladesh 53,000 hectares were destroyed
How did snowmelt contribute towards the Bangladesh flooding in 2022?
Abnormal snowmelt led to increase in discharge of River Ganges which combined with prolonged monsoons in 2022
How did urbanisation contribute to the Sheffield floods in 2007?
Sheffield is a heavily urbanised area with large expanses of impermeable surfaces which led to a built up of water on the surface. On 15th June drains became blocked and overwhelmed and alongside surface runoff flooded large areas of the city.
How does deforestation lead to flooding?
Deforestation reduces evapotranspiration which results in an increase in surface runoff and river discharge. Secondary issues are caused by new land use also increases flood risk i.e. soil compaction due to agriculture or animal grazing and increase urbanisation
How is deforestation impacting on flooding in the Amazon, Brazil?
The Tocantins River in the Amazon drainage basin showed a 25% increase in river discharge between 1960 and 1977 which is coincident with increased deforestation.
Which flooding case study is associated with the mis-management of river channels?
2011, Mississippi, Florida, USA
How has mis-management of the Mississippi lead to an increase in flood risk?
Management has included channelisation (widening/deepening river) and the construction of embankments. Methods have increase river velocity, increasing flood risk.
What were the impacts of the 2011, Mississippi River flooding event?
Flood in 2011 can be blamed on hard defences which left thousands homeless and killed 20 people and cost $2.8billion to repair
