The Narmada Dams in India
- Indian Government believes they'll bring many advantages to the status of india and be a major benefit for Indian state of Madhya Pradesh.
- However local tribes believe their way of life is under threat... why?
- Farmers can use water from lake to irrigate crops.
- Dams will make hydro-electric power that will be used in peoples homes.
- Jobs to build the dam will be created.
- The dams will provide clean drinking water for thousands.
- fish can live in the lake and provide food for people.
- Rare wildlife and historic sites destroyed.
- Fertile land and forests flooded.
- Lake behind dam spreads diseases.
- Poor people wont benefit from the dam and lake.
- Mud and grit will get stuck behind the dam.
- Some water from lake lost through evaporation.
- 20,000 people forced to move for lake!
Water Managment Scheme, River Mississippi
Flowing 3,000km, one of the most heavily engineered rivers in the world. Wing dykes of tough stone built from river banks to trap sediment, form new land to narrow the channel, increase flow, deepen channel by erosion. Also involved strengthening of 1,600km of levees, and raising them to 15.8m, particularly at confluences with its tributaries. Parts straightened by cutting off meanders. Course shortened by 300km to increase flow. Revetments line the banks to protect them from erosion. Over 100 dams have been built on tributaries upstream to hold back water in reservoirs and reduce water pressure on the levees. Afforestation in upper basin delays surface runoff, reducing amount of water reaching water. Borrowpits dug out of floodplain allowed to flood at times of high discharge. Dredging removed silt from centre of channel.
Levees offered protection by reducing flood risk, farmland, crops, animals, house and settlements are safeguarded.
However levees limit access to river so local people are inconvenienced and they are unsightly. Bonnet Carre spillway has reduced floodrisk at New Orleans. Dredging has deepened the river channel by removing sediment and stabilization of the banks by revetments has decreased amount of silt entering the channel by erosion so shipping channels are kept open. Vital to the transport of bulky cargo along Mississippi and has helped the economy of the region. Dams have created HEP for cities and industry.
Hydrological Cycle - Deforestation in Amazonia
Removal of tress reduces interception and precipitation reaches the earth's surface more quickly, rapid surface run off. Thus heavy convectional rainfall infiltrates the ground and percolates into rocks, increasing groundwater store. Less water returned to atmosphere by transpiration and this could cause a decrease in amounts of rain and eventually lead to drought. Surface water store is increased as rain flow into rivers rapidly. Felling removed protection of the soil, so soil erosion occurs, into rivers causing rise in river discharge and flooding. Evaporation from ground surface and soil increases, as theres less vegetation cover.
Main reason for clearance is the need of natural resources by a growing population. Demand for tropical hardwoods such as Mahogany in MEDCs like the USA and Europe so large scale logging occurred. Transnational companies log areas to grow cash cops, raise beef cattle or extract minerals on a commercial scale. Rainforest land also needed for settlement. Gov policy involved resettlement of some of Brazils landless people. Roads such as Trans Amazonian highway is vital for movement of timber, agricultural and mineral commodities and also carve corridors in rainforest - opening up Brazil. Deforestation for transport, HEP generation, farming and mining needed for developing economy and to raise countries GNP and erase foreign debts.
River Control - River Nile, Egypt
Its 5km long and 100metres high, built at Aswan to regulate the flow of the Nile. Construction of the dam created Lake Nasser - reservoir. Small dams have been built on some of the DISTRIBUTARIES on the Nile Delta. Jonglei canal made in upper White Nile valley to bypass swampy Sudd area.
Aswan dam needed to even out water supply along Nile valley and to prevent annual flooding in lower Nile caused by heavy rainfall increasing discharge downstream. Joglei canal essential to reduce water loss in a marshy area during floods in upper White Nile. Lake Nasser has water storage used for drought. Also created an irrigation system to enable Egypt to increase food production to keep pace with a rapidly growing population. HEP generation vital to improve economy and raise GNP. Also necessary to improve navigation alone the Nile from seasonal to year round benefitting trade and tourism.
Effects on people - farmers
In lower Nile have gained - irrigation system allows all year growth, tripling food production from the desert and providing and increased income. Area of land that can be irrigated has increased. Small dams on DELTA DISTRIBUTARIES prevent sea water getting into soil and damaging crops, thus safeguarding food production and minimising SALINISATION.
Some have lost - need to buy chemical fertilisers to replenish soils with nutrients lost through loss of silt deposited during flood. Many at risk of contracting snail fever.
Lake Nasser given new fishing industry, providing abundant, protein rich food supply for Egyptians. The livelihood of coastal fishermen deteriorated as sardine fleet has been halved because less nutrient rich sediment reaches delta and Mediterranean sea.
A landform created by the action of the sea - Old
Created by erosion. Area of resistant rock being the majority and being sandwiched by softer rock, this softer rock erodes faster and thus leads initially to a piece of land that sticks out into the sea. Once the headland is formed this leads to a shallow water wave cut platform in front of the headland. Shallow water at headland reduces speed of wave (friction with sea bed). Wave bends, erosive power focussed on headland, wears away one area of headland forming cave on sides of the structure. Hydraulic action and attrition will erode the caves to form an arch. Eventually weathering and erosion will mean the arch will collapse leaving a stack, Old Harry.
What will happen in the future?
Erosion will continue, focussed on headland, another arch may be created where there is currently a cave shown on the diagram. Old Harry itself being made of chalk will weather from the top downwards. Weathering will eventually lead to the formation of a stump. With time, whole headland will be eroded leaving a wave cut platform behind.
Change in employment opportunities in a region ove
Describe how the employment opportunities have changed
Coal mining (primary), steel manufacturing (secondary industry) dominated region. Industries have declined now... only one colliery remaining: tower at hirwaun and one steel works at port talbot, creating massive unemployment. Light industry on industrial estates involving manufacturing of consumer goods such as confectionery, shoes, electrical goods etc. has created jobs and reduced unemployment. Also offered jobs to both genders. Development of tourism introducing tertiary sector to the area.
Why have the changes taken place?
Exhaustion of resources, then mechanisation of mines, efficient machinery reduced need of human labour. In 70's and 80's successive Conservative Government policies worsened employment situation through closure of pits, thousands of job losses, loss of union power leading to miners' protests. Long term devastating effect on mining communities. Competition from other fuels such as gas, oil, HEP and nuclear power = fall in demand for coal, used less as a domestic fuel, causing further unemployment. More recent decline fueled by competition from Poland and USA who can produce coal more cheap. Steel industry declined as a result of automation and modern technology. To diversify employment structure, gov designated S.Wales as a Development Area eligible for grants and subsidies.
Overseas Investment in an MEDC
Welsh Development Agency secured 1.7 billion investment by LUCKY GOLDSTAR a South Korean MULTINATIONAL company, for an electronics complex in South Wales. Two factories planned: Tv monitor production plant and semiconductor factory. Promised 6,100 jobs as DIRECT EMPLOYMENT. A further 15,000 jobs as INDIRECT EMPLOYMENT through supplier and component companies, and services was est. as a result of POSITIVE MULTIPLIER EFFECT. Due to financial problems in S. Korea, Semicon plant site lies dormant while a suitable tenant is sought.
Affects on people and environment
2,000 jobs created for redundant coal miners and steelworkers. Reduced unemployment rate. Less than half of direct employment promised has materialised, disappointed potential employers. South Korean investment acted as a catalyst in strengthening of local economy. Lucky Goldstar succeeded in focusing attention of other investors and businesses on Newport. Influence on improvement on road links and on the increase in house prices in Newport. Boosted residential rental market of the city and influenced an increase in residential development. POSITIVE MULTIPLIER EFFECT = rise in demand for local goods and services, leading to expansion of local industries and thus increased wealth of community. Local Authority benefited from more taxes, spent on improving amenities.
A country or region outside the UK where changing
Newly Industrialising Country and is one of the tiger economies of South East Asia. Since end of war, its changed rapidly, initially most people were employed in primary sector such as farming. Primary employment has fallen from 66% to 15% since 1950 while manufacturing has risen from 6% to over 35%. Many now work in factories in MULTINATIONAL COMPANIES such as samsung. Tertiary industry is also on the rise, 50% of people working in this sector.
People expected to work long hours - one day off a week and one week holiday a year. School leavers dont work as farmers with their families anymore but move to large cities for work - RURAL TO URBAN MIGRATION. They sleep in dormitories in factories and not get alot of leisure time.
Environmental cost - increased pollution and industrial accidents. Chemical plant leaked into river KUMI. Korean people demonstrated about the environment for the first time.
S. Koreas cities are developing rapidly and spreading into countryside - standard of living increases this referred to as URBAN SPRAWL. Korean companies spreading worldwide - MULTINATIONALS. Samsung located mobile phone factory in China to take advantage of their cheap and strong work force. South Korea is moving into the 5th stage of Rostows model of development.
Bangladesh Floods - background info.
75% of the country submerged including large areas of Dhaka.
Flooding in July and August caused by intense monsoon rainfall, snowmelt, heavy rains over Bang. in Sept. raising high discharge in 3 rivers.
Gagnes in July was 13m, then 15m in August.
Brahmaputra exceeded 15m in July and August and September.
Level of sea in Bay of Bengal also high, slowed down normal flow of water which resulted in higher depths in rivers.
Result: longer duration of flood, increased damaging impacts. 67 days - water was above danger level. Started flooding in June - September.
Made worse by: extraction of groundwater for irrigation lowered water table and caused land to subside by about 2.5m.
Use of water for irrigation upstream led to higher peak flow with much shorter lag times and a greater frequency of floods.
Deforestation in the Himalayas has increased run off.
Bangladesh is low-lying. Coastal plain is 1-2m above sea level and densely populated.
Coastal areas at risk of flooding more due to global warming which could raise sea level.
Bay of Bengal narrows to the north.
Tropical storms with winds up to 225km/hr cause storm surges and huge waves up to 8m.
Sea is very shallow due to silt being deposited by rivers (forming the delta).
When sea levels rise, water from rivers can't escape this and floods inland.
Destroyed crops, food supplies lost, drinking water contaminated (sewage and rotten bodies).
Half a million cattle drowned.
Fishing boats destroyed.
Over 4million people starved and diseased.
000's of houses washed away. 00's of villages wiped out. 130,000 people killed.
Roads and bridges destroyed and electricity cut off for months.
Emergency electricity and telephone links didnt work. Early warning system proved ineffective.
Shelters provided by gov insufficient. Relief couldn't reach some because of poor transport.
Poor country thus cant afford to prepare for and protect against flooding.
Yellow booklet: more effects!
Flood brough considerable health risk from water bourne diseases such as cholera and diarrhoea. Worst hit areas - flood removed whole villages and large areas of farmland swept out to sea.
Large % crops lost so farmers had no food to survive. Roads flooded making it hard for relief to be brought into rural areas. After the flood Bang. had a deficit of 2.2millions tonnes of rice and this had to be replaced by imports or foregin aid.
When the water went down, large areas were left infertile.
Dhaka badly affected, eastern area flooded and 45% having water at roof level! Poor were particularly affected, losing income and having to borrow money and suffering from diseases. Lack of clean drinking water and food shortages. Some tried to stay with relatives but others were left to find open space, often on higher ground where diseases spread fast as it was very crowded.