How and why do the effects of flooding and the responses to it vary?
Floods and their effects vary by;
1.
Size
2.
Location
The impact of flooding tends to be more severe in Poor countries (LEDC – Less
Economically Developed Countries).
In Rich countries (MEDC – More Economically Developed Countries) the responses to floods are quicker, with the responses coming from within the local area and within the country.
In poorer, less developed countries , attempts to reduce the effects of the floods can be delayed and require international effort.
Long term responses will show similar differences as a result of:
1.
Differences in wealth
2.
Differing abilities to afford flood protection measures.
They do not have experts to build dams and control the river
Floods have advantages and disadvantages.
Advantages - 1) Deposit silt on the land to make the soil fertile.
2) Water the land so crops will grow.
Disadvantages – 1) People are drowned.
2) Property is destroyed.
3) Farmland is ruined.

Causes
th
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Both rivers which meet at Tewkesbury were overwhelmed by the volume of rain that fell in the surrounding areas, up to 5 inches (130 mm) over a 5 day period, which started on Friday 20 July
Effects
- All four access roads to the town, the Gloucester road (old A38) from the south, the A38 to the north-west, the B4080 north-east to Bredon and the A438 east were flooded and impassable.
- The only major remaining access was via what was once a railway line, although many braved a route through a residential estate, where the flood levels were low enough to wade through.
- For the first time in its 100-year history the Mythe Water Treatment
Works flooded, resulting in the loss of tap water for 140,000 homes over a period of two weeks.
- Despite the lack of access several businesses remained open, most notably the Old Plough pub on Barton Street, where the clientele lined much of the street
- The Association of British Insurers has said the total bill for the June and July floods could reach £2bn.
Responses
- Emergency services rescued people in boats
- People cleared the shelves of bottled water in supermarkets
- Authorities delivered sandbags to residents
- Water companies across the UK sent in tankers to help thousands of homeowners whose supplies had contaminated.
- An emergency Hotline was set up for victims
- The Red Cross delivered food parcels.

Flooding in England
Flooding in many parts of England June-July 2007 covered the most area ever experienced.
The depth did not reach the record levels of 1947, but the scale of the areas affected reach new highs.

Surface water flooding in Hull

Widespread disruption and damage to more than 7000 houses and 1,300 businesses in Hull

River Don burst its bank, flooding
Sheffield and Doncaster.

Flooding in Derbyshire, Lincolnshire and
Worcestershire.

Highest official rainfall total was 111 mm at Fylingdales (North Yorkshire). Amateur
Networks recorded similar totals in the
Hull area.

There were fears that the dam wall at the
Lilley Reservoir near Rotherham would burst.

Widespread disruption to the motorway and rail networks.

In the following days the River Severn and tributaries in Gloucestershire,
Worcestershire, Herefordshire and
Shropshire broke banks and flooded surrounding areas.

River Thames and its tributaries in
Wiltshire, Oxfordshire, Berkshire and
Surrey flooded.

Flooding in Telford and Wrekin,
Staffordshire, Warwickshire and
Birmingham.

The highest recorded rainfall was
157.4mm in 48 hours at Pershore College
(Worcestershire).

Flooding in Bangladesh
Bangladesh gets severe flooding regularly.
Annual flooding is expected in this low lying country, located on the delta of the
Ganges.
Floods in 1988, 1998, 2004 and even 2007, stand out due to the scale and how severe the floods were.
Bangladesh case study - 2004
Date:
The 2004 floods were from July-September
What happened? Over ½ of the country was under water.
Physical causes of floods

Most of the country is the huge flood plain and delta of the rivers Ganges and
Brahmaputra

70% of the total area is less than 1 metre above sea level.

Rivers, lakes and swamps cover 10% of the land area.

Tropical cyclones and storm waves cause heavy rain and coastal floods.

Snowmelt in the Himalayas in late spring and summer

Heavy monsoon rains, especially over the uplands including the Himalayas
Human causes of floods

Deforestation in Nepal and Tibet

The building of dams in India

The impact of global warming

Urbanization creates obstacles to the free flow of water

Flood defences such as embankments.
Effects:

In July 2004 flood 40% of capital Dhaka underwater

60% of country submerged

600 deaths reported

30 million homeless (Total Population: 140 million)

100,000 in Dhaka alone suffered from diarrhoea from mud and raw sewage left by floodwaters.

Later in year, Bangladesh had its heaviest rain in 50 years (35cm fell in 1 day on 13 September)

Death toll rose to 750

Dhaka Airport, roads and railways flooded. Bridges destroyed.

All this hampered relief work that followed

Damage to schools and hospitals was put at $7 billion

In many rural (country) areas – rice crop (the main food) was washed away.

Other important food supplies eg. Vegetables lost as well as jute and sugar, cash crops (food to sell).

Immediate Responses:

Food supplies, medicines, clothing and blankets were distributed – from
Bangladesh

Effect of flood on the transport system made this difficult.

Local communities began to rebuild their homes.

Disease from contaminated water remained a major threat.

International aid began to arrive.

United Nations launched an appeal for $74 million (only 20% received by
September)

An appeal by WaterAid sought to supply water purification tablets and posters highlighting the hygiene risks in flood water.
Long term responses:

Embankments (walls of soil) were built along the river – they have not achieved their goal of protecting against floods.

Flood warning system and providing flood shelters has been more successful

Flood shelters are areas of raised land where people can move to temporarily with their cattle and have access to items such as dried food, get clean water
(before supplies are contaminated).

LAND USE IN THE DRAINAGE BASIN OF THE RIVER TEES
The river Tees is in North-East England. Its source is on Cross Fell, the highest point in the Pennines at 893m above sea level, where rainfall is over 2000mm a year. It flows eastwards for over 90kms into the North
Sea.
Land use in the uplands of the river Tees
The steep slopes and lack of flat land in the valley floor make the building of communications and settlement very difficult. Rough pasture and peat covered moors dominate the upland parts of the Tees basin. As a result population density is low and settlement is widely dispersed. The main economic activities are:-
Hill sheep farming
Hill sheep farming is the main economic activity. The land is too steep to use machinery, the growing season is too short and the soils too thin and acidic for growing crops. Above about 400m is found open moorland where the sheep roam freely in the summer. Below 400m there are fields bounded by traditional dry-stone walls. Only where the slopes are less steep is the pasture improved by fertilisers, the occasional crop of hay or barley is grown and a small herd of dairy cattle is grazed. Hill farmers face problems:- a) a short growing season b) poor soils and steep slopes
Water supply
In the Tees valley the water quality is very high, which makes it suitable for use as a water supply for homes and industry. The high rainfall also gives a reliable water supply. The deep v-shaped valleys are ideal for building reservoirs. There are several large reservoirs e.g. Cow Green reservoir in the upper dale, built to supply water to the heavy industries on Teesside. The reservoir also helps to flood control. Storing water in the reservoir helps to reduce flooding in the lower course.
Tourism
Recreation and leisure are important users of the uplands. Large tracts of heather moorland are managed for grouse shooting and the Pennine
Way long distance footpath crosses the area. Other attractions include the spectacular waterfalls of High Force and Cauldron Snout. The visitors provide much needed employment for local people in the hotels and restaurants, as car park attendants, visitor centre staff and shop

assistants. However, tourism also brings traffic congestion, litter and overcrowding and soil erosion on the hillside from trampling over the land.
Quarrying
Quarrying is important in the Upper Teesdale. A tough igneous rock called dolerite crops out in this part of the dale and makes an ideal roadstone.

To tackle floods Engineers talk of ‘Managing’ rivers
There are 2 methods of tackling floods:
1.
Hard engineering (using technology to control rivers)
2.
Soft engineering (working with the natural processes of the river)
Hard engineering approaches tend to give immediate results and control the river, but are expensive.
In the future though they can make problems worse or create unforeseen ones.
Soft engineering is much cheaper. It is the more sustainable option (can keep doing it) as it does not interfere with the river’s flow.
(Create a Table like the one below – write the good and bad points about each form of flood management)
Hard Engineering Soft Engineering
Pros
Cons
Hard Engineering
It often needs considerable amounts of money and high levels of technology to reduce the flood risk. Methods used to reduce the risks of flooding are:-
1) Building levees – banks along the river.
2) Building dams and reservoirs to store of water.
3) Straightening the river to make it flow quickly and carry away more water.
4) Deepen river channel – hold more water
5) Build embankments – soil walls
6) Build flood walls – protect towns and cities
Dams and reservoirs have huge control over a river.

The natural flow of water is prevented by a dam (a concrete barrier across the valley), water fills the area behind it and is released or held depending on circumstances such as current or expected rainfall.

Dams and reservoirs are normally constructed as part of a multi-purpose project rather than with just a single aim in mind.

Straightening meanders are a smaller scale approach to managing rivers. Meanders are long winding courses.

Like following a route in a car, a semi-circular way is longer than a straight one.

So water in a meander takes longer to clear an area, than water in a straight river.

One solution to flooding is to remove meanders and straighten river artificially.

This makes the river follow a shorter, straight section and abandon its meandering course.
Soft Engineering
1.
Plant trees to stop the water reaching the river as quickly.
2.
Allow river to flood farmland – save city areas
3.
Do nothing
Soft engineering works with the river’s natural processes to reduce the effects of flooding. It doe not attempt to gain control over the river.
Do Nothing can be necessary in poor countries. In richer areas it can mean money set aside to help people after a flood event.
Flood warnings and preparation
This helps people prepare in advance of a flood.
The Environment Agency (EA) identifies areas at risk of flooding and issues warnings.
Information was given on TV, local radio and Internet during the 2007
Tewkesbury flood.
Floodline Direct sends messages to registered users
 Flood watch issued on 20 July at 18.32
 Flood warning 20 mins later.
 Allows people time to turn off gas, water and electricity; take possessions upstairs; gather together important papers; take some basic precautions against flooding.
 EA Website gives info on how to prepare for floods, what to do during and after one.
Zoning
Floodplain zoning occurs were there are often floods. Landuse takes the flood risk into account.

 Clear areas are left beside the river, with
 grazing land next to it.
 Playing fields and recreational areas are next.
 Further up the hill you have roads and carparks.
 Higher up you have Industry.
 The highest away from the flood zone is housing.
Draw diagram of zoning
Case Study – The Three Gorges Dam
Dimensions
Area flooded
Cost
181m high and 2.3 km wide
632 km²
$25.5 billion
Built Started 1994; finished 2006
Increased depth 110m (reduced to 80m when flood risk downstream)
The Three Gorges Dam was built at Yichang on the River Yangtse.

The capacity of the reservoir should reduce the risk of flooding downstream from a 1-in-10 year event to a 1-in-100 year event.
This will benefit over 15 million people living in high risk flood areas.
It will also protect over 25,000 ha of farmland.
Benefits
Dam is already having a positive impact on flood control.
Navigation and power generation have improved.
Problems
It has had problems. The Yangtse used to carry over 500 million tonnes of silt every year. Up to 50% of this is now deposited behind the dam, which could quickly reduce the amount of water the reservoir can hold.
The water in the reservoir is becoming heavily polluted from shipping waste discharged from cities. Eg. Chongqing pumps in over 1 billion tonnes of untreated waste per year. Toxic substances from factories, mines and waste tips submerged by the reservoir are also being released into the reservoir.
Controversially, over 1.4 million people were forcibly removed from their homes to accommodate the dam, reservoir and power stations.

These displaced people were promised compensation for their losses, plus new homes and jobs. Many have not yet received this, and newspaper articles in China have admitted that so far over $30 million of the funds set aside for this has been taken by corrupt local officials.
Case Study – The Kielder Transfer Scheme
Kielder Water Reservoir, Britain's biggest artificial water store, lies in
Northumberland, within 5 km of the Scottish border. Completed in 1982, it transfers water form the River Tyne southwards to the rivers Wear and
Tees. Kielder was built in response to pressure from industries in the northeast, such as British Steel and ICI, who predicted big increases in water demand. But as heavy industry declined so too did the demand for water, winning Kielder the reputation of being Europe's biggest boating lake. Only twice in its history has Kielder been used to transfer water to the Tees, first in 1983 and then 1989.
On 26 April 1996 Yorkshire Water Services (YWS), in response to the water shortage in Yorkshire, announced its decision to develop a £50 million water transfer scheme from the River Tees to the River Ouse.
Inter-river transfers are used to redistribute water from areas of surplus supply to those where there is a shortage of water (deficit). Such projects may cause serious environmental and social impacts.
Yorkshire Water's scheme threatens to: o o o o
Introduce alien species into the river environment
Spread disease, damaging fish stocks
Change the natural character of the river ecosystem
Increase flood risk
As water is removed from the Tees it will be replaced by transfers from
Kielder Water Reservoir on the River Tyne. The transferred water to

supply Yorkshire may therefore originate in the Tyne. The scheme is intended to be operational whenever there is insufficient water available from Yorkshire Water's existing sources.
There could be effects on water quality, fisheries, landuse and landscape, archaeological and cultural heritage, noise, air quality and traffic.
As a result of using water from the reservoir there may be a reduction in water quality, an impact on the visual beauty of the lake and disruption for recreational users.
Several scarce species of caddisflies, mayflies and stoneflies have been recorded and may be effected.
Channel works or the construction of new facilities on the River Tees could lead to loss of agricultural land and disruption of agricultural activity which may cause financial problems for farmers. Construction of new pipes will also cost money.
Construction of pipelines will involve land take and production of spoil which has to be disposed of. Construction activities could cause shortterm disruption to farming activities with potential for damage to drainage systems and fences. During construction of pipelines and pumping stations vehicles used create pollution, noise and disruption to other road users. Longer term impacts include soil compaction, topsoil loss and localised noise from the operation of new pumping stations.