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Enhancing SmartConservation ™ : Green Infrastructure Plan Development Robert Cheetham Avencia Incorporated Clare Billett Natural Lands Trust Funding provided by William Penn Foundation. Overall Objectives. - PowerPoint PPT Presentation
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Enhancing SmartConservation™ :Green Infrastructure Plan
Development
Robert CheethamAvencia Incorporated
Clare BillettNatural Lands Trust
Funding provided by William Penn Foundation
Overall Objectives
Develop a green infrastructure plan for SE PA made up of hubs and corridors.
Develop a methodology to use in the site-to-site assessment to score SmartConservation™ sites based on their proximity to these hubs and corridors
– but we’ll defer this until the hubs and corridors are established.
Hubs
1. Existing Protected Lands(gov & NGO - not ag. lands)
1. Lands with top 20% of region-wide SmartConservation mapped natural resources
2. All CNAI-PNDI Locations
Protected Lands
Conservation Resource Lands
PNDI Lands
Merged Hubs
Protected Lands
PNDI
Cons. Resource Locations
Merged Hubs
merge
Before merge
After merge
Corridors - The Real Question
How can we connect the hubs?
Where should the corridors be?
How far is any corridor location from a hub?
Distance vs. ‘Cost Distance’
• Distance ‘as-the-crow-flies’ is really not the distance that we want.
• We want to account for ‘barriers’ in the landscape as well as factors that overcome barriers.
• We also want to account for ‘density’ of nearby protected lands.
• We can use the concept of ‘travel cost’ to model this.
Linear Distance
• Like spinning a ruler around a center
What is Cost Distance ?
Concept: It costs more to travel through certain ‘cells’
Input: HubsFriction/Permeability/Cost Surface
Output: Represents Accumulated Least Costfrom source location (hub)to destination location (another hub)
What is Cost Distance?
Cost: Barriers to travel
(including factors that might ‘reduce’ barriers)
Higher cost values means greater barrier
Examples: Roads
Wind
Railways
Salinity Gradient
Water
What is Cost Distance?
Cost Distance to Sample Site from other protected lands
How is it used? – an Example
Least Cost Path from Sample Site to Protected Lands
How is it used? – an Example
Green Infrastructure Development Method - TASKS
1. General Permeability Layer Development
2. Corridor Identification Methodology
3. Aquatic Corridor Development
Task 1 Objectives
Develop a map layer that represents the degree of permeability for terrestrial movement of animals which migrate through the landscape
…but also encapsulates the size, shape and degree of protection for each hub
Barriers
1. Roads Class2. Active Railways3. Higher Order Streams4. Water bodies
Barriers are 50% of Travel Cost
Streets
Active Railways
Ordered Streams
Water bodies
Relative Travel CostRelative Travel Cost
0
20
40
60
80
100
120
Barrier
Co
st
Combine Barriers
Density
1. Roads2. Active Railways3. Higher Order Streams
Density is 50% of Travel Cost
Density – 500m
• Density calculation done with a radius of 500 m.
Density – 1000m
• Density calculation done with a radius of 1000 m.
Density – 1000m w/ CLASS NLT selected this one to use
• Density calculation done with a radius of 1000 m and using CLASS as calculation factor.
Density – 2000m
• Density calculation done with a radius of 2000 m.
Building the Corridors
Basic Principles:
• Corridors connect Hubs
• Corridors occupy the Least Cost Path between two hubs
• Corridor networks are calculated at different scales (regional/ subregional /local)
• When multiple corridors are available, the one that combines the best average conservation value, plus destination hub value, will prevail.
Preliminary Impedance
Hub Proximity Values• Merged
protected land sites with overlapping donut buffers of 1km and 2 km and values of 50% and 10 % respectively.
Overlap region with cumulativeproximity values
Conservation Resource Value
Modified Impermeability
+Modified Impedance -= ( )Barriers Conservati
on ValueHub Proximity
Modifying Impermeability Again• Adjust Cost Layer
by using Maximum Cost in 150m radius around each cell
• Create ‘Snowplow’ effect to encourage paths through areas with best average conservation value and least average
barrier costs -- across the entire corridor width of 300m (or 1100ft)
Least Cost Path w/o modification
2000 ft
300 ft
60 ft
Least Cost Path w/ modification
Neighborhood Maximum
5 86
3 50
1 51
8
In Out
Neighborhood Maximum
1 4 3 11
3 3 2 13
1 2 1 11
1 1 2 11
0 1 1 10
3 4 4 34
3 4 4 34
3 3 3 23
1 2 2 22
1 2 2 21
Modifying Impermeability Again• Adjust Cost Layer
by using Maximum Cost in 150m radius around each cell
• Create ‘Snowplow’ effect to encourage paths through areas with best average conservation value and least average
barrier costs -- across the entire corridor width of 300m (or 1100ft)
Least Cost Path w/o modification
2000 ft
300 ft
60 ft
Least Cost Path w/ modification
Preliminary Impedance
Modified Impedance• Conservation
Resource Value, Protected Land ‘Zone of Influence’ values have been subtracted.
Building the Green Infrastructure Network
Basic Principles:• Adjacent and overlapping hubs should be treated as a single hub
• ‘Travel Cost’ between hubs is a function of both the barrier types and the density of the barriers.
• Barriers have different relative impact values depending on their impermeability (e.g. relative amount of traffic or similar measure such as width, etc.)
• Density and Barrier type impact value each comprise 50% of the total corridor cost.
• Density is calculated at using a 1000m search radius
• Corridor Cost is reduced by 2 factors:– Conservation Resource Value– Proximity to Hubs
• Corridor Cost is based on the average cost and values for the entire 300m corridor width, (not just one cell width and then buffered as with other least cost path green infrastructure processes (e.g. TCF, MNRD, etc)).
Discussion Points - This Afternoon
P1: Road Class Barrier Cost (value)
P2: Railway Barrier Cost (value)
P3: Ordered Stream Barrier Cost (value)
P4: Water Body Barrier Cost (value)
Green Infrastructure Development Method - Next Steps
1. General Permeability Layer Development
2. Corridor Identification Methodology
3. Aquatic Corridor Development
Task 2 Objective
Establish corridors between connecting hubs based on hub size
classes
Hubs
Conceptual Corridor Network
Create a Network of Corridors using the following parameters:
1. For each Hub > 1000 acres, select all other hubs within 30 miles
2. Draw ‘least cost path’ to each3. Create a Cost Corridor4. A = Corridor Conservation Value5. B = Hub Conservation Value6. C = Length, Cost Length7. Corridor Value = Average (A + B)8. Select Top 39. Repeat
Connect Large Hubs
Create a Network of Corridors using the following parameters:
1. For each Hub > 500 acres, select all other hubs within 15 miles
2. Draw ‘least cost path’ to each3. Create a Cost Corridor4. A = Corridor Conservation Value. 5. B = Hub Conservation Value6. Corridor Value = Average(A + B)7. Select Top 58. Repeat
Connect Medium Hubs
Create a Network of Corridors using the following parameters:
1. For each Hub > 100 acres, select all other hubs within 3 miles
2. Draw ‘least cost path’ to each3. Create a Cost Corridor4. A = Corridor Conservation Value. 5. B = Hub Conservation Value6. Corridor Value = Average (A + B)7. Select Top 58. Repeat
Connect Small Hubs
Least Cost Path - ExampleLeast cost path -- between source & destination hubs
Least Cost Path - ExampleLeast cost path -- between source & destination hubs
Cost Weighted Corridor - Example
• Corridor calculation using the cost weighted method with minimum extent radius of 10 cost units
Cost Corridor between source & destination hubs
Cost Weighted Corridor - Example
• Corridor calculation using the cost weighted method with minimum extent radius of 10 cost units
Cost Corridor between source & destination hubs
Discussion Points - This Afternoon
CI 1: Network scales
Network Scale
Hub Size Search Radius # of Corridors per hub
Large >1000 acres
30 miles 3
Medium >500 acres
10 miles 3
Small >250 acres
5 miles 3
Green Infrastructure Development Method - Next Steps
1. General Permeability Layer Development
2. Corridor Identification Methodology
3. Aquatic Corridor Development
Task 3 Objectives
Create
special aquatic corridors
that connect hubs using riparian corridors
Aquatic Corridors are built from…
1. Ordered Streams2. Water bodies3. Floodplains4. Wetlands5. Hydric Soils
Stream Order 1-2
Stream Order 3-5
Stream Order 6-12
Flood Plains
Wetlands
Hydric Soils
Water Bodies
Sample Corridor
Sample Corridor
Choosing Aquatic Corridors
The best Aquatic Corridors have:
• Fewest Barriers
• Highest Aquatic Value
Aquatic Barriers are ...
1. Dams (>5ft): 5 points
2. Bridges/CulvertsStream Order 1-2: 3 pointsStream Order 3-5: 2 pointsStream Order 6+: 1 points
Bridges/Culverts 1-2• Bridges 1-2 were
defined by extracting intersection points of roads and streams of order 1-2
Bridges/Culverts 3-5• Bridges 3-5 were
defined by extracting intersection points of roads and streams of order 3-5
Bridges/Culverts 6-12• Bridges 6-12
were defined by extracting intersection points of roads and streams of order 6-12
Dams
Aquatic Conservation Value
Hub Proximity Values• Merged
protected land sites with overlapping donut buffers of 1km and 2 km and values of 50% and 10 % respectively.
Overlap region with cumulativeproximity values
Basic Principles:
Aquatic Corridors are Special and the best ones should be highlighted
The Travel Cost approach is not appropriate for aquatic corridors due to the limited number of possible routes
Aquatic corridors are made up from combinations of:- Ordered Streams- Water bodies- Floodplains- Wetlands- Hydric Soils
Aquatic corridor “barriers” are Dams and Bridges/Culverts
The best aquatic corridors are:- Less impeded by dams and other barriers- Have higher aquatic conservation value- Lead to hubs of high conservation value
Highlighting Special Aquatic Corridors
Discussion Points - This Afternoon
AQ1: Aquatic Corridor Value Formula
Input Layers Value Factor Maximum
Conservation Value Layers
Aquatic Conservation Value 0 - 10 2 20
Hub Proximity 0 – 10 2 20
Barrier Layers
Dams 5 # of dams
20
Bridges/Culverts 1-3 # of bridges/culverts