1) Water balance = relationship between inputs and outputs of a drainage basin.
Precipitation = Q (runoff/discharge) + E (evapotranspiration) +/- changes in storage.
2) Stores and transfers of water in the hydrological cycle.
3) Recap water cycle (simple animation),
Maximum Sustainable Yield: The maximum level of extraction that can be maintained indefinitely for a given area.
water mining - sustainable? sea level?
Key terms: evaporation, transpiration, evapotranspiration, condensation, precipitation,interception, infiltration, percolation, surface runoff, throughflow, baseflow, groundwater.
Drainage Basin: The area drained by a river and its tributaries.
Drainage Divide: Also known as a watershed, it is the line defining the boundary of a river or stream drainage basin separating it from adjacent basin(s).
5) Features of drainage basins: source, tributary, confluence, channel, floodplain, mouth, delta, distributaries.
6) River profile & characteristics: upper, middle & lower valley. Bradshaw model. Waterfalls.
7) River discharge: define, measurement (cumecs).
8) Make notes about the factors affecting the hydrograph: basin shape/size, drainage density, human influence, slope gradient, climate, soil type, vegetation. How do these affect the lag time and peak discharge?
10) Purpose & use of hydrographs in predicting floods and the frequency of occurance of floods.
CASE STUDY: Bangladesh flooding
See slide show below.
Include - Geographical location, physical & human causes, effects & preventative efforts.
Case study notes (password required)
Case Study: Aswan Dam - Egypt
Costs/benefits of the dam
Case study notes (password required)
Case Study: 3 Gorges Dam - China
- Read these links to make case study notes on:
- the purpose,
- costs & benefits of the dam.
- has it been worth the cost & disruption?
Damming the Mekong, Laos building new megadam (BBC)
1) Factors affecting erosion: velocity, gradient, human activities.
2) Levees, meanders & oxbow lakes.
3) Notes about deposition: deposition features (deltas, braided channels, levees), reason for increased deposition & benefits brought by deposition..
4) Human modifications of floodplain & effect on flooding
- urbanisation & impermeable surfaces - reduced infiltration, faster & increased runoff.
- extraction of water - irrigation, wells
- River channel adjustments - building development, bridges,
- Chinas River Diversion - video
5) Management Strategies
Storm channels through cities
Case Study: London, UK
short guides looking at some of the causes & solutions to flooding in London
Flood barriers such as the Thames Barrier, London
Yangtze River: China.
3 Gorges Dam upstream to hold back floodwater & release it slowly.
Jingjiang flood diversion scheme - area allowed to flood to protect large urban areas downstream.
Mississippi flood gates opened (Telegraph 2011)
Practise Exam Q
You may use your books, research etc to answer this - make it thorough & treat it as a learning execise rather than a test.
Read this article for an introduction to the unit Groundwater. Published by http://www.yearofplanetearth.org/
Unsustainable use of groundwater: India
New reserves of groundwater discovered: Namibia
Pollution of groundwater and health implications: Bangladesh
Wetlands: Areas that are regularly saturated by surface water or groundwater, including freshwater marshes, swamps and bogs.
Case Study: Kissimmee River Restoration
Where is the Kissimmee river.
How, why & when was it altered?
Why and how is it being restored? (and at what cost?)
- Read & make notes about the the impact on a global scale that fertilisers are having.
- Why have they become so essential for food supplies, but also for economies that rely on agriclture?
- What is micro-dosing and how can it help overcome?
Case study (password required)The Guardian.co.uk - The Andes
Mini-series looking at water shortages in Peru - causes, effects and some ideas about what can be done.The Andes: Retreat of the glacier
bbc.co.uk: Chiles water conflicts between mining & agriculture in the Atacama Desert.
Conflict over water - International Scale
Case Study (password required)
The Nile River Basin
Extra reading: Water Conflict and Cooperation/Nile River Basin (2003)
Past Exam Q essay:
“The lower courses of rivers are more important to people than the upper courses.”
Discuss this statement with reference to located examples. [20 marks]
Lake Mead & the Hoover Dam
Water wars in the USA: BBC video clip about state conflicts over the use of the Rio Grandes water.