9.7 Urban Drainage Flashcards
What is the traditional method of removing surface water run off?
Traditionally, a network of underground pipe systems were used to remove surface water run off.
What is a problem with traditional water drainage systems?
They did not take into account how useful the water could be.
What are some of the potential uses water could have?
Water resource management.
Provided a habitat for wildlife.
Landscaping
Community facilities
List 3 natural landscapes:
Forests
Wetlands
Grasslands
What do natural landscapes do?
They trap precipitation
What do natural landscapes allow?
They allow precipitation to infiltrate the ground.
True or false: urban areas have natural landscapes to trap precipitation and allow it to infiltrate the ground?
False: urban areas do not have areas like this.
Instead of natural landscapes, what do urban areas have?
They have impermeable surfaces like roads, car parks and rooftops.
What does SUDS stand for?
Sustainable Urban Drainage Systems
What are SUDS?
These are modern approaches to urban drainage. They are a more holistic approach and try to manage surface water and mimic natural drainage.
Where do greater and more intense amounts of precipitation tend to fall?
Greater amounts of intense rainfall tend to occur in cities rather than the surrounding rural area.
Where are pollutants from urban areas going?
They get into rivers and into the ground which is bad because ground water pollution is hard to clean up.
What are 3 adaptations of urban areas in regards to water shedding?
Sloping roofs
Smooth rounded guttering
Cambered roads
What acts like high density drainage systems?
Storm sewer systems collect water and act like high density drainage systems.
What gathers speed and erosional power the further underground it travels?
Water
What happens when water leaves the storm drains?
The water empties into streams which fill rapidly.
What two things are reduced because of reduced infiltration?
Soil water and groundwater levels.
What type of water feeds streams during dry periods?
Soil water and groundwater.
What is reduced in streams as a result of a lack of soil water and groundwater?
The base level flows.
What does a storm hydrograph for an urban river show?
A river with a flashy discharge but a low base flow.
What are urban areas more likely to have after heavy rainfall?
They are more likely to have flooded rivers.
Why are more people now at risk of flooding?
The increase of population and urban growth as well as more frequent severe weather because of climate change will lead to more people being at risk to flooding.
According to the Asian Development Bank, how much of the Asian population will be at risk to flooding by 2025?
350 million people in Asia will be at risk from inland flooding by 2025.
What has the Red Cross stated about almost half of the natural disasters that it dealt with in 2014?
Almost half of the natural disasters that the Red Cross dealt with in 2014 were caused by floods.
What can a high river flow cause?
This can cause a flooding and erosion of the river bank during wet periods.
What will a decreased river flow during dry weather cause?
This will cause harm to fish and other aquatic life.
What can high water temperatures do to ecosystems?
They can disturb ecosystems.
What can very high flows do?
They can overload the foul water system resulting in raw sewage on the surface.
What are 6 causes of water pollution?
Road salt Viruses from pet waste Pesticides and nutrients Heavy metals Oil, grease and toxic chemicals Sediment
Where do the polluting pesticides and nutrients come from?
They come from parks and gardens.
Where do the polluting heavy metals come from?
Car exhausts.
Where do the oil, grease and toxic chemicals come from?
They come from cars.
Where does the sediment come from?
River bank erosion and building sites.
What can pollutants do?
Harm fish and wildlife.
Kill native vegetation.
Foul drinking water supplies.
Make recreational spaces unsafe and unpleasant.
