Paper 1- Essay Plans Flashcards
With reference to a river catchment you have studied, assess the potential factors which can impact upon the flood hydrograph
INTRO:
- Define a flood hydrograph and it’s key features
- Systems- inputs, flows, outputs
- introduce the river exe- facts
1- Precipitation type and intensity.
- leads to shorter lag times and higher peak discharge
- Rive exe recieves high rainfall- 1295mm
- saturated soil leads to more surface runoff
- steep relieve of exmoor- flashy hydrograph
2- Geology and Soils
- impermeable bedrock and thin soils on Exmoor, reduces infiltration, more surface runoff
- increases peak discharge and steepens rising limb
3- Land use and Urbanisation
- Exeter and Tiverton urban growth, more impermeable surfaces, more runoff
- Reduces lag time and raises peak discharge
- Agriculture- compacts soil, reduces infiltration
4- River management Schemes
- Wimbleball Reservoir regulates river flow, stores water during heavy rainfall, reduces peak discharge and increases lag-time
- Drainage Ditches on exmoor leads to rapid runogg, regeneration schemes like the Exmoor Mires project has encoredged infiltration
Assess the potential causes and impacts of changes to the water balance within a tropical rainforest you have studied- 20 marks
INTRO-
- Talk about the water balance- inputs, outputs, storage
- facts on the Amazon Rainforest
1- deforestation
- due to agriculture
- removes vegetation -> reduces infiltration, interception and evapotranspiration, leading to increased surface runoff and reduces soil moisture storage
- Amazon 17% of forest cover lost
agricultural practices- soil compaction increasing runoff
- Climate Change
- alters inputs (precipitation), more intense storms and prolonged dry seasons
- higher temperatures, more evaporation and soil desolation
- feedback loops- forest dieback, reduces transpiration, less rainfall, further dieback
3- impacts on river flow and flooding
- increased runoff leads to higher river discharge ad flashier hydrographs and flooding.
