flooding and drought revision –
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Flooding and drought Revision – . see s-cool.co.uk A Level G eography. Also – BBC Bitesize , and search for drought. Causes of floods. 6 causes – g lobal warming deforestation tsunamis monsoon ice melt h igh drainage density tides urbanisation - PowerPoint PPT PresentationTRANSCRIPT
Flooding and drought
Revision –
see s-cool.co.uk A Level
Geography
Also – BBC Bitesize, and search for drought
Causes of floods6 causes – • global warming• deforestation • tsunamis• monsoon• ice melt• high drainage density• tides• urbanisation
Deforestation in detail – infiltration, transpiration, stem flow, runoff, soil enters river.
Flood hydrograph – what it shows, how it works
Effects of floodsPrimary effects• Physical damage – Can damage any type of structure, including bridges, cars,
buildings, sewerage systems, roadways, and canals.
Secondary effects• Water supplies – Contamination of water. Clean drinking water becomes scarce.• Diseases – Unhygienic conditions. Spread of water-borne diseases.• Crops and food supplies – Shortage of food crops can be caused due to loss of
entire harvest.[4] However, lowlands near rivers depend upon river silt deposited by floods in order to add nutrients to the local soil.
• Trees – Non-tolerant species can die from suffocation.[5]
• Transport - Transport links destroyed, so hard to get emergency aid to those who need it.
Tertiary/long-term effects• Economic – Economic hardship, due to: temporary decline in tourism, rebuilding
costs, food shortage leading to price increase, etc.
Solutions to flooding – small and large scale
• the creation of embankments (artificial levees) along the river to increase channel capacity and restrict flood waters - however since 1957, 7,500km of flood embankments have been constructed and yet many were breached in the 1998 floods;
• constructing flood protection shelters (large buildings raised above the ground) to shelter both people and animals
• emergency flood warning systems and plans made for organising rescue and relief services;
• providing emergency medical stores in villages• building flood proof storage sheds for grain and other food supplies• dam construction upstream and major embankments around Dhaka have been
suggested however lack of money has meant that these suggestions have not been taken further.
Case study: Bangladesh (see Geobytes)
Case study: Your country
Causes Effects Solutions
Causes of drought
3 causes
Effects of drought
3 effects
Solutions to drought
3 solutions
3 case studies
Place, date, causes and effects
Possible – Dustbowl, Philippines, Horn of Africa
Imageshttp://www.pupilvision.com/yeareleven/hydrograph.htm
http://geobytesgcse.blogspot.com/2006/12/flooding-in-ledc-1998-floods-in.html