718788
Descrição
Mapa Mental por RachBenson, atualizado more than 1 year ago
|
Criado por RachBenson
mais de 10 anos atrás
|
|
Factors affecting the
shape of a hydrograph
- Antecedent rainfall
- Heavy rain falling on a soil which is saturated from a previous period of wet weather
- Produces steep rising limb
- Produces steep rising limb
- Heavy rain falling on a soil which is saturated from a previous period of wet weather
- Impermeable rock types
- such as granite & clay - tend to have higher drainage densities.
The higher the density the faster the water reaches the main
river channel, causing rapid increases in discharge.
- such as granite & clay - tend to have higher drainage densities.
The higher the density the faster the water reaches the main
river channel, causing rapid increases in discharge.
- Size of drainage basin
- A small drainage basin tends to respond more rapidly to a storm
than a larger one, so the lag time is shorter.
- A small drainage basin tends to respond more rapidly to a storm
than a larger one, so the lag time is shorter.
- Vegetation
- Varies with season. In summer there are more leaves on
deciduous trees, so interception is higher and peak discharge
lower. Plantations of coniferous have a less variable effect.
- Varies with season. In summer there are more leaves on
deciduous trees, so interception is higher and peak discharge
lower. Plantations of coniferous have a less variable effect.
- Urbanisation
- Human impact. Reduces lag time and increases peak discharge. Impermeable surfaces (concrete/tarmac)
- Drains/sewers
- Transport water rapidly to river channels, reducing the lag time
- Transport water rapidly to river channels, reducing the lag time
- Straightening of river channels and lining of concrete - leads to faster
delivery of water downstream of the urban area and increases the risk of
flooding in downstream areas.
- Drains/sewers
- Human impact. Reduces lag time and increases peak discharge. Impermeable surfaces (concrete/tarmac)
Quer criar seus próprios Mapas Mentais gratuitos com a GoConqr? Saiba mais.