703132
Descrição
Mapa Mental por Andrew_Ellinas, atualizado more than 1 year ago
|
Criado por Andrew_Ellinas
mais de 10 anos atrás
|
|
Rivers, Floods and Management:
River Drainage and Storm
Hydrograph
- What is River Discharge?
- The volume of water in a
channel passing a particular
point in a given period of
time.
- Values are expressed in cumecs (cubic
metres per second)
- The calculation is: discharge (m3 per second)
= cross-sectional area (m2) x velocity (metres
per second)
- The volume of water in a
channel passing a particular
point in a given period of
time.
- What Factors Affect River Discharge?
- Distance Downstream: In humid environments, river
discharge increases downstream. Main reason for
increase in water are caused by tributaries joining the
main river.
- Climatic Characteristics: Snowfall results in time delay as it is being
stored for a long time until snowmelt happens and there is a sudden
surge in discharge. Temperature affects evaporation rates and
vegetation growth
- Land Use: Afforestation reduces discharge and make it more constant. Urbanisation increases
discharge because water is transferred rapidly over impermeable surfaces such as tarmac-and
through pipes and sewers.
- Water Abstraction (Removal): This is for domestic use and
the irrigation of crops, this reduces discharge. This can be
seasonal, with greater demand for water in summer months.
- Channel Modification: Constructing a reservoir regulates the discharge and makes it
more constant. The channel itself might also be modified to reduce flood risk e.g. channel
straightening and enlargement tend to increase discharge.
- Distance Downstream: In humid environments, river
discharge increases downstream. Main reason for
increase in water are caused by tributaries joining the
main river.
- The Storm Hydrograph
- This is a graph that shows the
discharge of a river following a
storm event
- Characteristics that affect hydrographs:
Anexos de mídia
Quer criar seus próprios Mapas Mentais gratuitos com a GoConqr? Saiba mais.