Decision making and conditions for good GI Dr Maggie Keegan Head of - - PowerPoint PPT Presentation

Decision making and conditions for good GI

Dr Maggie Keegan

Head of Policy and Planning, Scottish Wildlife Trust mkeegan@scottishwildlifetrust.org.uk

Natural Capital Standard for Green Infrastructure

Dr Maggie Keegan

Head of Policy and Planning, Scottish Wildlife Trust mkeegan@scottishwildlifetrust.org.uk

How do we achieve consistently good GI design in development?

Natural capital standard for green infrastructure

• an evaluation tool

to assesses the quality and quantity of GI in development

GI factor = Total area of green and blue infrastructure Total development surface area

An evaluation tool

Context

Bo01

GI factor = Total area of green and blue infrastructure Total development surface area

An evaluation tool

GI factor =

∑ ((Area a x weighting factor) + (Area b x weighting factor) + etc) Total surface area of development footprint

An evaluation tool

Weighting factor depends on ecosystem services

• Carbon sequestration
• Aesthetics
• Pollination
• Water quality
• Air quality
• Slowing water movement
• Biodiversity
• Soil quality regulation
• Local climate regulation

Ecosystem services

Sealed surface = 0 Permeable paving = 0.2 Green roof (HBV) = 0.6 Amenity grassland = 0.3 Naturalised grassland = 0.6 Shrub bed LBV = 0.4 Vertical greening HBV = 0.4 SUDS HBV= 0.8 SUDS LBV = 0.3 Planted native tree or shrub = 0.4 Stand of 10+ trees (retained ) = 1 Retained native hedgerow = 1 Planted native hedgerow = 0.4 Community growing area/allotment = 0.6

Weighting factor

• ecosystem services

SUDS HBV = 0.8 Naturalised grassland = 0.6 Planted n. tree = 0.4 Shrub bed HBV = 0.8 Permeable paving = 0.2

GI weighting factor

Surface Weighting (W) Stand of 10+ trees / woodland retained HBV 1 Retained native hedgerow (≥ 3 native species) 1 Retained native hedgerow (≤ 2 species) 0.8 Stand of 10+ trees / woodland retained LBV 0.8 Retained species rich meadow 0.8 Retained non-native hedgerow 0.8 Retained native tree 0.8 SuDS HBV 0.8 Community growing area/allotment 0.8 Rain garden HBV 0.8 Retained non-native tree 0.8 Shrub bed HBV 0.8 Stand of 10+ trees / woodland planted HBV 0.8 Green roof HBV 0.8 Established wildflower meadow 0.8 Vertical greening HBV 0.6 Stand of 10+ trees / woodland planted LBV 0.6 Water feature (e.g. pond) - naturalised, HBV 0.6 Amenity grassland with bulbs / naturalised grassland (e 0.6 Shrub bed LBV 0.4 SuDS LBV 0.4 Amenity grassland 0.4 Green roof LBV 0.4 Rain garden LBV 0.4 Planted native tree 0.4 Planted native hedgerow (≥ 3 native species) 0.4 Planted native hedgerow (≤ 2 species) 0.3 Vertical greening LBV+ high maintenance 0.3 Planted non-native hedgerow 0.3 Planted non-native tree 0.3 Naturalised play area 0.3 Permeable paving/gravel/ with green element 0.2 Herbaceous flower bed border 0.2 Permeable paving / gravel / partially porous surface 0.2 Water feature LBV 0.2 Sealed areas e.g. tarmac, concrete surfaces

Low score High score

Examples of GI ratio in development

Berlin

• New development = 0.6
• Commercial = 0.3
• Public facilities = 0.6
• Nursery school and daycare centre = 0.6
• Secondary school = 0.3

Context

Applications

• Quality assurance
• Improving GI and biodiversity in new build housing,

schools, university grounds, retail and business parks

• Baseline vs development analysis
• Retrofitting
• Climate change adaptation analysis (e.g. surface water

movement, urban heat island)

• Analysing ecosystem service value of existing places
• Improving air quality

A worked example

GI ratio = 0.26

Thank you

mkeegan@scottishwildlifetrust.org.uk