Flooding Case studies
Cockermouth, UK - Rich Country (MEDC)
A massive downpour of rain (31.4cm), over a 24-hour period triggered the floods that hit Cockermouth and Workington in Cumbria in November
What caused all the rain?
The long downpour was caused by a lengthy flow of warm, moist air that came down from the Azores in the mid-Atlantic. This kind of airflow is
common in the UK during autumn and winter, and is known as a ‘warm conveyor’. The warmer the air is, the more moisture it can hold.
What else helped to cause the Cumbrian Floods?
· The ground was already saturated, so the additional rain flowed as surface run-off straight into the rivers
· The steep slopes of the Cumbrian Mountains helped the water to run very rapidly into the rivers
· The rivers Derwent and Cocker were already swollen with previous rainfall
· Cockermouth is at the confluence of the Derwent and Cocker (i.e. they meet there)
The effects of the flood
· Over 1300 homes were flooded and contaminated with sewage
· A number of people had to be evacuated, including 50 by helicopter, when the flooding cut off Cockermouth town centre
· Many businesses were flooded causing long-term difficulties for the local economy
· People were told that they were unlikely to be able to move back into flood-damaged homes for at least a year. The cost of putting right the damage was an average
of £28,000 per house
· Insurance companies estimated that the final cost of the flood could reach £100 million
· Four bridges collapsed and 12 were closed because of flood damage. In Workington, all the bridges were destroyed or so badly damaged that they were declared
unsafe – cutting the town in two. People faced a huge round trip to get from one side of the town to the other, using safe bridges
· One man died– PC Bill Barker
Responses to the flood
· The government provided £1 million to help with the clean-up and repairs and agreed to pay for road and bridge repairs in Cumbria
· The Cumbria Flood Recovery Fund was set up to help victims of the flood. It reached £1 million after just 10 days
· Network Rail opened a temporary railway station in Workington
The ‘Visit Cumbria’ website provided lists of recovery services and trades, and people who could provide emergency accommodation
Management of future floods at Cockermouth
£4.4 million pound management scheme
New flood defence walls will halt the spread of the river
Funding from Government and local contributors
River dredged more regularly to deepen the channel
New embankments raise the channel height to reduce the likelihood of extra floods
New floodgates at the back of houses in Waterloo street
Pakistan, Asia - Poor Country
huge area of Pakistan affected by flooding. The floodwater slowly moved down the Indus River towards the sea.
Continuing heavy rain hampered the rescue efforts. After visiting Pakistan, the UN Secretary General, Ban Ki-moon, said that this disaster was worse than anything he’d ever seen. He described the floods as a slow-moving tsunami.
The effect of the floods
· At least 1600 people died
· 20 million Pakistanis were affected (over 10% of the population), 6 million needed food aid
· Whole villages were swept away, and over 700,000 homes were damaged or destroyed
· Hundreds of thousands of Pakistanis were displaced, and many suffered from malnutrition and a lack of clean water
· 5000 miles of roads and railways were washed away, along with 1000 bridges
· 160,000km2 of land were affected. That’s at least 20% of the country
· About 6.5 million acres of crops were washed away in Punjab and Sindh provinces
The responses to the floods
· Appeals were immediately launched by international organisation, like the UK’s Disasters Emergency Committee – and the UN – to help Pakistanis hit by the
· Many charities and aid agencies provided help, including the Red Crescent and Medecins Sans Frontieres
· Pakistan’s government also tried to raise money to help the huge number of people affected
· But there were complaints that the Pakistan government was slow to respond to the crisis, and that it struggled to cope
· Foreign Governments donated millions of dollars, and Saudi Arabia and the USA promised $600 million in flood aid. But many people felt that the richer foreign governments didn’t do enough to help
· The UN’s World Food Programme provided crucial food aid. But, by November 2010, they were warning that they might have cut the amount of food handed out, because of a lack of donations from richer countries
Unprecedented levels of monsoon rainfall led to the catastrophic floods in Pakistan’s Indus River basin in July 2010 - the nations worst flood since 1929. An area the size of England was affected.
|An informative collection of maps and hydrographs.|
Class task - interpret the storm hydrographs.
The Geography of Pakistan
- Pakistan is situated in the northwest of the South Asian subcontinent.
- The country can be divided into three main geographical areas; the Indus river plain; the two provinces of Punjab and Sindh, and the Balochistan Plateau.
- Home to the famous K2 (Mount Godwin), the second highest peak in the world.
- The climate is generally arid though it is influenced by the south east Asian monsoon. Half of the annual rainfall occurs in July and August, averaging about 255 millimeters in each of those two months.
- Gained independence from the British India colony in 1947.
- Earthquake prone zone along the Himilayan convergence fault line.
- Provinces of Gilgit-Baltistan, Khyber Pakhtunkhwa, Punjab and Sindh, and the Azad Jammu and Kashmir were all affected by the floods.
A monsoon depression (low pressure system) formed over the Bay of Bengal, crossed India and reached Pakistan by the 27th July 2010. The rainfall intensified over the subsequent two days as another low-pressure system from the west converged with the monsoon depression, enhancing rainfall. Over 203 mm (8 inches) of rain fell in only three days in the northwest of Pakistan creating a flash flood.
Other potential anthropogenic causes such as enhanced climate change, dams and deforestation must be taken into consideration. Sarhad Awami Forestry Ittehad (SAFI), an organisation state that illegal deforestation took place 2007-2009 under Taliban control. According to reports the Tarbela dam became blocked by illegally felled timber, reducing its storage capacity and heightening the severity of the floods.
- 23 % of crops were destroyed.
- Enormous mudslides took place on steep slopes in mountainous areas.
- Reviving mangroves - replenishment of water and nutrients to natural mangroves that were previously diminishing since the construction of the Tarbela dam on the Indus. 170,000 hectares of mangroves had been lost in the Indus delta of the last 50 years, partially due to poor management of water flow along the Indus, starving the delta of sediments and allowing saline seawater to infiltrate the delta.
- 20% of tree plantations created in the 2009 – 2010 afforestation project were ruined - leaving hill slopes susceptible to erosion, reducing interception of rainfall and increasing the intensity of future floods.
- Loss of breeding grounds - the floods washed away vital wetland breeding grounds for wading birds and fish.
- Habitat loss - an estimated 80% of reptile and small mammal habitats were affected within the Swat and Panjorka river catchments.
- Pollution - a 62000 litres of petroleum and 44300 litres diesel from pumps.
|Mass subsidence in the highlands|
- 1781 fatalities.
- 2966 people injured.
- 20 million people affected in over 11000 villages.
- £1.5 billion agriculture loss.
- 1.9 million houses damaged.
- Entire villages were submerged resulting in more than a million people displaced from their homes.
- Spread of disease epidemics.
- Infrastructure was demolished. Temporary structures such as rope bridges were constructed in the aftermath.
- Crops were ruined, some livestock drowned and food reserves were spoiled, creating food shortages that manifested to hunger and malnutrition. Food aid was donated from the UN.
- Livelihoods dependent upon timber extraction, agriculture, fisheries and infrastructure collapsed.
An adaptable case study
This case study can be applicable to other major topics within the curriculum such as flooding, climate change and natural hazards.
The following film report by the Guardian can be used to provide a balanced overview of the positive and negative impacts of the floods:
The findings of as investigation carried out by the Pakistan Wetlands Trust was documented in August 2010. This is a recommended resource for teachers wanting to do background reading in order to compile a case study for A Level Geographers.