- Hydro electric power produced. Provides power for growing cities eg Las Vegas.
- Cheap electric for industry
- Power used to pump water over the rocky mountains to phoenix. This has lead to expansion.
- Increase in agriculture. Farmers have increased their yields.
- Transport. Provides new links between Nevada and Arizona
- Desalination plant built in Mexico which was expensive.
- Crop surplus, thus affecting crop prices
- Increased traffic congestion.
- Terrorist threats.
- New expensive bridge
- Huge artificial lakes act as sancturies for waterfowl such as pintail.
- The land was useless before.
- Clean water which is a) better for your health.
b) more suitable for drinking and irrigation as sediment stays on river bed.
c) Renewable and pollution free.
- Sediment is trapped behind the dam. Requires dredging which is costly.
- Salinisation is ruining the soil.
- Natural landscape has been lost.
- Water evaporates leaving salt which means farmers have to use more fertilisers.
- Huge artificial lake has increased tourism. 8 million visitors per year.
- Lake Mead is a popular caravan destination.
- Prevents some flooding as snow melt is controlled.
- HEP has meant cities have expanded.
- Still some flooding.
- Salinity level increasing which causes problems downstream for example at the mouth of the gulf of California. The saline levels are high so mexicans can't use the water :(
- Each state requires water. In the 1922 compact 6 states signed it to share out the water.
- California gained the most as it had the largest population.
- When the allocations of water were calculated it was based upon a rainy year so water was exaggerated.
- Some states were not left with enough water becuase the figures were wrong.
Factors considered when locating a dam
- Consider the are behind the dam incase of flooding
- Consider the flooding of historical sites etc ancient burial site.
- Consider the workforce.
- Consider the distance to farms/urban areas for HEP or irrigation.
- Deep, narrow valley to reduce cost of building it. Narrow valley =smaller surface area for evaporation.
- Strong, impermeable rock such as granite.
- Not on tectonic plates.
Site and situation of Edinburgh
- Built around and on the crag and tail. This was a good defensive site when the castle was built as it was hard to climb and the loch also protected the castle.
- Plenty of open space for expansion over the moorland.
- Lots of hills and hollows which means there are a lot of green spaces which gives Edinburgh a nice appearance.
- Has a good central location as several main roads meet from London, Aberdeen and Glasgow.
- Good airport, railway and port for importing goods in the past.
Distribution of cities in the UK
- Around the coast a) for trade- London for trading with Europe. Glasgow with America
- b) for fishing and oil- Aberdeen
- c) ship building- Glasgow
- Near rivers for transportation of raw materials and communication.
- Access to raw materials such as coal and iron- Glasgow
- Historical/Political purposes- Edinburgh and London
- In southern areas because the land is flatter.
Distribution of cities in Sao Paulo.
- Along the coast for fishing and trading- Rio de Janeiro.
- New little settlements have located along the trans Amazon highway.
- Planned cities- Brasilia
- Inland settlements developed as route centres for coffee trading.
- Near the coast because most of the land is covered with dense vegetation and has poor infrastructure.