Analysis of benefit distribution in Blue Green Cities: A spatial toolkit
Dr Lan Hoang
Department of Engineering
LAA meeting, Newcastle25 November 2014
Centre forSustainable Development
Outline
How the Blue-Green Cities project explores flood risks and the multiple benefits of flood risk strategies to cities
Multiple benefits from Sustainable Urban Drainage SystemsGreen Infrastructure
Project Aim: Develop and rigorously evaluate strategies for managing flood risk that deliver multiple benefits as part of urban planning and renewal
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Water Sensitive Cities
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Department of EngineeringCentre for Sustainable Development
Multiple Benefits of Green Infrastructure
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Multiple Benefits of Green Infrastructure
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Grey versus Green Solutions (Portland , Oregon)
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The three point approach
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Grey versus Green Solutions
Urban interdependencies
Functional Complexity: the linkages across
the urban components which can influence
their primary function
Source: OTAK
Relational Complexity: the governance
linkages across the corresponding planning
and management agencies
Source: eastpdxnews.com
Functional Complexity (Physical)•Reduces heat island effect•Reduces temperature in building•Protects roofing material•Increases biodiversity•Retains stormwater, relieves downstream sewers•Sequesters CO2
•More maintenance
Relational Complexity (organizational)•Local and distant effects•Temporal effects affecting planning•Who benefits?•Who manage the benefits/disbenefits?•Agency and owner interactions
Green Roofs
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Interactions with the Urban System
Implications
Soil Moisture Low High SaturationAir temperature Low High Low High Low HighWater storage
capacity++ +++ + ++ - -
Pollutant trap ++ ++ +++ +++ + +Thermal building
insulation ++ ++ ++ ++ + +
Thermal exchange + ++ + +++ - +
Carbon sequestration
+ + ++ +++ - -
Noise attenuation +++ +++ ++ ++ + +
Biodiversity Cold and drought resistant
ecosystem
Drought resistant
ecosystem
Cold resistant ecosystem
Multiple species
- -
Visual amenity + ++ +++ +++ - -
Potential functions of green roofs under different conditions.+, ++, +++ denote the potential level of functions from low to high; - denotes small or zero functioning
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Department of EngineeringCentre for Sustainable Development
Benefit intensity- based on the cumulative spatial distribution of benefits
Developing benefit profiles and overall benefit intensity
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Case Study, Johnson Creek Portland, Oregon USA
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Foster Road Floodplain Restoration - Before
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Foster Road Floodplain Restoration - After
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Spatial distribution of benefits in a GIS tool
Project extent
Avoided floodAccessibility to green space
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Traffic impacts
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Noise propagation
LANDSAT-based analysis
Summer Winter
Cooler micro-climate
Warmer micro-climate
Time-slide example: 2013
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Overlay of physical benefits of site
Location of benefit occurrences
Intensity of benefit occurrences
Beneficiaries
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Other functions
•Visualise EPA SWMM model
•Run SWMM model and display
results in QGIS
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Conclusion
•Multiple potential Green Infrastructure benefits
•Toolkit based on existing tools can be used to analyse spatial and temporal
distribution of those benefits
• Next step:
•Fully integrate functions into the toolkit
•Analyse GI benefits under the blue and green conditions
•Analyse GI benefits for different scales
•Use Multi-criteria Analysis to aggregated the benefits
Thank You for Listening