Causes and impact of flooding– Case studies

Question 1

Flooding of south Asia, 2007

- why do parts of South Asian floods most years, usually in late summer

Answer 1

• South Asia has a monsoon climate– eighty percent of rain falls in just four months
• South Asia is low-lying land, particularly Bangladesh where 90% of land is less than 10 m above sea level
• melting snow and ice from the Himalayas in the late summer months increase the Brahmaputra River discharge
• ## August two thousand seven, the flooding was particularly severe in Bangladesh and India

Question 2

Physical factors were the main course… (SOUTH ASIA FLOOD)

Answer 2

1. the monsoon came suddenly after a very dry, early summer
2. there was heavy rainfall– Assam had a record 169.5 mm in 24 hours on 22 July, and 900 mm in total for july
3. the long duration of heavy rainfall completely saturated soil, Increasing surface run-off and increasing discharge
4. the peak discharge of the River Ganges and Brahmaputra coincided, Which increased the river discharge downstream

Question 3

Human activities made the flooding worse… (SOUTH ASIA FLOOD)

Answer 3

1. deforestation in the part and Himalayas meant less rainfall was intercepted, Which increased discharge
2. the growth of urban areas, due to migration, also increased surface run-off
3. collapse of old earth dams in Madhyra Pradesh, India, caused further flooding

Question 4

Social impacts of the South Asia flood

Answer 4

1. over 2000 people died, the death toll was-many reasons e.g. Many people were reluctant to evacuate (as they would have to leave their land and livestock unattended) and many children drowned because they couldn’t swim. Poor transport links meant evacuation was/.
2. as Wales became polluted with sewage, there was a lack of clean drinking water. Over 100,000 people court waterborne diseases.
3. an estimated 25 million people were made homeless
4. 112,000 houses were destroyed in India and, As porous mud bricks became saturated by floodwater
5. Dhaka ( Bangladesh’s capital) was inundated, Especially the poor districts and shantytowns near the river
6. children lost out on education as 4000 schools were affected and 44 schools would totally destroyed

Question 5

Economic impacts of the South Asia flood

Answer 5

1. the cost of the flight was estimated at US$1 billion including damage to crops and property
2. actuaries were closed around Dhaka, due to flood damage and lots of raw materials. any of the poorest workers became unemployed
3. there was widespread loss of livestock. Since 80% of Bangladeshis rely on and agriculture, many lost their livelihoods
4. 550,000 ha of land couldn’t be planted with rice at peaktime

Question 6

Economic impacts of the South Asia flood

Answer 6

1. the cost of the flight was estimated at US$1 billion including damage to crops and property
2. actuaries were closed around Dhaka, due to flood damage and lots of raw materials. any of the poorest workers became unemployed
3. there was widespread loss of livestock. Since 80% of Bangladeshis rely on and agriculture, many lost their livelihoods
4. 550,000 ha of land couldn’t be planted with rice at peak time, because are flooded fields. A lower rice crop meant to the world price of basmati rice rose by 10%
5. 10,000 km of road were destroyed. Landslides blocked roads in the Highlands of Nepal and Assam.
6. Debt increased, Both individually and Nationally

Question 7

Environmental impacts of the South Asia flood

Answer 7

1. the theatre positive fertile silt on the floodplain

2. rivers were polluted with sewage

Question 8

Flooding of Carlisle, Cumbria, 2005

facts

Answer 8

• the River Eden runs through North Cumbria and reaches the senior Carlisle
• the drainage basin of the River Eden is very large so catches a large volume of rainfall, leading to a high river discharge
• some parts of the basin has steep sides, So water runs quickly down to the river
• there are many streams that drink quickly into the river making the lag short
• on 8 January 2005 eighth of January two thousand five the River Eden flooded Carlisle. The flood interval of such a large flood is about 200 years

Question 9

Physical factors were the main cause… (CARLISLE FLOOD)

Answer 9

1. there was heavy rainfall on the 6th January, 36 hours 200 mm of rainfall was recorded, which was the equivalent of four months rain
2. rain fell on saturated ground so the water didn’t soak into the ground that ran straight off into the river
3. this caused a very high peak discharge (over 1520 cumecs) compare to an average discharge of 52 cumecs

Question 10

That human activities make the flooding worse… (CARLISLE FLOOD)

Answer 10

1. Carlisle is a large built-up area, with impermeable concrete and tarmac surfaces, and little soil of vegetation. This meant that there was a little infiltration of rainfall and high surface run-off, which increased discharge
2. drains and sewerage systems that overflowed in some areas - becoming a source of flooding themselves. 25% of the flooding problems what are associated with overflowing drains.

Question 11

Social impacts of Carlisle flood

Answer 11

1. three people died
2. over 3000 people were made homeless for up to a year and thousands of personal possessions were damaged. Living in temporary accommodation disrupted lives in many ways e.g. travel arrangements were disrupted, people separated from community networks and friends, And they had trouble receiving post
3. children lost out on education as four schools will severely flooded. Newman Catholic school didn’t reopen to Easter.
4. there was an increase in stress-related illnesses following the flood

Question 12

Economic impacts of the Carlisle flood

Answer 12

1. it took about a year to repair the damage to homes and repairs cost over £100 million
2. 350 businesses had to shut down as there was no electricity, telephone service or transport. Trade activities from Carlisle railway station were suspended
3. United Biscuits, the largest employer in Carlisle, Was flooded with 3 m of water that is caused over £5 million of damage. 33/1100 employees lost their jobs.
4. 70,000 addresses had no power. The sewage works, police station, Fire station and council officers were severely flooded.
5. 80 buses were destroyed. Many roads and bridges were damaged e.g. Warwick Road

Question 13

Economic impacts of the Carlisle flood

Answer 13

1. it took about a year to repair the damage to homes and repairs cost over £100 million
2. 350 businesses had to shut down as there was no electricity, telephone service or transport. Trade activities from Carlisle railway station were suspended
3. United Biscuits, the largest employer in Carlisle, Was flooded with 3 m of water that is caused over £5 million of damage. 33/1100 employees lost their jobs.
4. 70,000 addresses had no power. The sewage works, police station, Fire station and council officers were severely flooded.
5. 80 buses were destroyed. Many roads and bridges were damaged e.g. Warwick Road

Question 14

Enviromental impacts of the Carlisle flood

Answer 14

1. the flooding increased riverbank erosion in some areas

2. rivers were polluted and and rubbish and sewage