Urban drainage

Question 1

Why do urban areas experience more precipitation

Answer 1

• Warmer urban air can hold more moisture
• Dust and pollution creates more condensation nuclei
• Less vegetation = less evapotranspiration
• Less vegetation = less interception

Question 2

How does urbanisation impact the drainage basin storage areas

Answer 2

• Management of rivers; dredging, embanking and channelization increase storage capacity
• Less interception storage since vegetation has been replaced by impermeable surfaces
• Soil moisture storage reduced as less exposed surfaces and vegetation

Question 3

What are SUDS and what is their purpose

Answer 3

Sustainable Urban Drainage Systems are environmentally friendly replicas of natural drainage systems.
Designed to reduce and slow down surface runoff and allow pollutants to be naturally filtered.

Question 4

Name some examples of SUDS

Answer 4

• Swales
• Permeable roads and pavements
• Green roofs
• Infiltration trenches

Question 5

Describe some of the benefits of SUDS

Answer 5

• Reduce surface runoff; reduce flooding
• Prevent water pollution
• Create habitats for wildlife
• Recharge groundwater stores

Question 6

Describe the process of river restoration

Answer 6

Process of removing hard engineering adaptations; returning flood management to nature