Drainage

• What are SUDS

  It’s a drainage solution that provides alternate courses to the sewers and watercourses.
• what does SUDS aim for

  It aims to reduce surface runoff, improve water quality and enchanted biodiversity
• how does SUDS prevent run-off

  • pervious pavements rather than tarmac allow for water to permeate
  • Draining rainwater into grass from the roof allows for it to soak in
  • Reusing rainwater
  • Green roofs to decrease about of water running off roof
  • infiltration trenches
  • swales (grassed depressions) and basins (hold back storm runoff)
• What does SUDS stand for

  Sustainable urban drainage scheme
• what are infiltration trenches

  a type of SUD. these are excavated trenches with gravel for infiltration of water
• What Sustainable Urban Drainage Systems (SUDS) are used in Freiburg?

  • green roofs, permeable pavements, swales, detention basins
• What is river restoration

  It is the removal of all hard engineering adaptations to restore the rivers natural course

  Aim to improve drainage and flood management
• what are hard engineering river management strategies

  • river straightening to increase speed down stream
  • diversion spillway- using sluice gates in emergencies to reduce river discharge in times of high flow
• Why do urban areas experience more rainfall than rural areas?

  Due to the heat island effect which causes more air to rise. Pollution also increases the gases trapped which leads to precipitation
• what does a gentle hydrograph curve show

  • more likely to be a rural area
  • high absorbency
  • less surface run off
  • permeable land around the river basin
• what does a steep curve on the hydrograph show

  • most likely a urban area
  • lots of intensive rainfall in a shorter period
  • impermeable surfaces around
• What are the effects of urbanisation on drainage systems?

  Urbanisation increases runoff as areas are covered in tarmac or impermeable pavements, flood risk, water pollution, and reduces lag time in rivers.