3.2.3.5 Urban drainage Flashcards
1
Q
Features of an urban hydrographs
A
- tend to be flashy
- generally have a low base flow
- steep rising and falling limbs
2
Q
Main changes in urban drainage basins
A
- impermeable surfaces increases runoff
- decreased evapotranspiration as there is less plants
- artificial drainage systems reduces lag time
3
Q
Aims of SUDS
A
- store runoff and release it slowly (attenuation)
- increase infiltration
- filter out pollutants
4
Q
Examples of SUDS
A
- green roofs
- permeable paving
- wetlands (the best)
5
Q
Why are wetlands the best SUDS
A
- attenuate
- increase biodiversity
- treats pollution
6
Q
Issues associated with catchment management
A
- water pollution
- controlling river flows
7
Q
Cheonggyecheon context
A
- Seoul has a population of roughly 25mn (17k per km)
- built a highway over the river
- this eliminated evaporation and meant the only input to the river was waste
- 180,000 cars daily
- 2003 restoration project
- costed $281mn
8
Q
Environmental impacts of Cheonggyecheon restoration
A
- flood protection in the area
- reduction in urban heat island effect by 2.5 degrees
9
Q
Societal impacts of Cheonggyecheon restoration
A
- allowed in civil participation through designing tiles
- 15.1% increase in bus ridership
10
Q
Economic impacts of Cheonggyecheon restoration
A
- 200,000 shops removed
- increased number of businesses by 4%
- increased price of land by 50%
11
Q
What is the importance of Hanang river
A
- It is the final point of Cheonggyecheon where the river flows into wetlands
