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www.natlands.org
SmartConservation ™
____________________________________________
Building
Green Infrastructure Plansfor SE Pennsylvania
using ESRI products____________________
Clare BillettNatural Lands Trust, Media, PA
_________________
Robert CheethamAvencia Incorporated, Philadelphia. PA
Funding provided by The William Penn Foundation
Pennsylvania Department of Conservation & Natural Resources
Green Infrastructure
• Develop a Green Infrastructure Plan forSE Pennsylvania made up of NODES andCORRIDORS …
Objectives
… based on the concepts of • Least Cost Paths across a• Cost Surface which is made up of • Barrier Values minus Conservation Values• while accounting for the ‘ gravitational pull ’
or ‘attractiveness value’ of Nodes
1. Existing Protected Lands
2. Rarity Locations (PNDI or CNAI)
3. Top 20% of Ecoregionally SignificantEcological Conservation Resources
Node Development
Combines 3 Components
Protected Lands
merge
Protected Lands
Rarity
Best Cons. Resources
Merged Hubs
Before merge
After merge
Merging Nodes
1. Collate different Protected Lands data sources
3. Merge using the highest protectedness rank at each location
4. Smooth & aggregate compiled polygons
5. Generate size & shape values for polygons. Compile with protectedness values(ratio 15/15/70 for s/s/p)
Ranking Merged Protected Lands
ProtectedLands
Calculate FinalProtected LandScore
Calculate Area,Perimeter, Shape
Reclass Area to10 classes
ACRES1 0 - 82 9 - 133 14 - 184 19 - 255 26 - 356 36 - 497 50 - 728 73 - 1219 122 - 25910 260 +
SHAPEdblRoundedness = 35.4 *Sqr(pArea.Area) /pCurve.length
SHAPE 15%SIZE 15%PROTECTEDNESS 70%
Conservtn.StewardshipLands
PEC SEPAProtectedLands
DVRPC2003 Parks
DCNRBureau ofForestry
Convert to Raster
Convert to Raster
Convert to Raster
Convert to Raster
Set ProtectednessValues
Set ProtectednessValues
Set ProtectednessValues
Set ProtectednessValues
Expand
ReclassNoData!0
ReclassNoData!0
ReclassNoData!0
ReclassNoData!0
LocalMaximum orMerge(a,b,c,d)
PA_SP 8NPS 8USFWS 8CONSERVANCY: 7PA_SF 6USFS 6LOCAL 1/6PA_SGL: 5PRI_INHOLD: 1
OWNED 8Else 7
County 6State 6Federal 6Municipal 1Preserved Farmland 0
Special Resource Mngmnt. (S) 9Natural Area (N) 8Wild Area (W) 7Else 6
Reclass Values!1 and 0!ND
RegionGroup Convert toPolygons
ZonalMean
AVERAGE THE SCORE OF EACH PROTECTED LAND POLYGON
2. Each has different “values” for “protectedness”
Conservation Resource Lands
Lands for Rarity
Merging Different Node ComponentsThis process merges different nodes components into a single node layer.
Each node has a value for ‘protectedness’, rarity or conservation value (0-10 scale)
Protected Lands
Rarity
Top 20%
DEFRAGEMENT NODES split by narrow barriers
by expanding them 2 cells (60m or ~200 ft) and then contracting them again
CONVERT TO RASTER
CONVERT TO RASTER
CONVERT TO RASTER
RECLASS0 -- > NO DATA
RECLASS0 -- > NO DATA
RECLASS0 -- > NO DATA
LOCALMAXIMUMOR MERGE
RECLASS0 -- > NO DATA
RECLASS0 -- > NO DATA
EXPAND NODES2 CELLS(200 FT)
Polygon Nodes
REGIONGROUP
CONVERTTOPOLYGONS
ZONAL
MEAN
1. Collate different Node components2. Each has different 0-10 “values” which need to be
combined
3. Merge using the highest value at each location
So Far, So Good…
• How can we connect the nodes?
• Where are the corridors?
• How do we find and use the Highest Conservation Values &Lowest Barrier Valuesbetween the nodes?
But The Real Work isGreenway Corridor
Development
Distance vs. ‘Cost Distance’
• We DON’T want to use Linear Distance ( as-the-crow-flies )
• We DO want to account for the spatial arrangement of ‘conservation value’ and ‘barriers’ in the landscape.
• We also want to account for the ‘attraction’ of any Nodes that are nearby.
• We can do this by using the concept of‘travel cost ’ or ‘cost distance ’ across a ‘cost surface’
So What is Cost Distance ?
ConceptIt costs more to travel through certain ‘cells’
InputsSources & Destinations – NodesFriction/Permeability (Barriers-Resources) - Cost Surface
OutputsLeast Cost Paths &Cost Corridorsbetween source and destination nodes
What is Cost Distance?
Costs
Barriers to travel. The greater the barrier, the higher the ‘ cost ’
examplesRoadsRailwaysStreams/Rivers/Waterbodies
an example -- Cost Distance from Source to Destination Node
How is Cost Distance Used ?
SOURCE NODE
COST SURFACEBarriers MINUS
Conservation Resources + Node Influence
LEAST COST PATH from Source to Destination Node across COST SURFACE
How is Cost Distance Used ?
3-Step Corridor Development Process
1. Developing the Cost Surface
2. Developing a Corridor Hierarchy
3. Aquatic Corridors * – To Be Added Manually Later
* Aquatic Corridors are Special Cases
Developing the COST SURFACECONCEPT
A data layer that represents the degree of permeability forterrestrial movement of animals as they migrate throughthe landscape …
…and acknowledges that each Node should have a degree of attraction or ‘ gravitational pull ’
…where the gravitational pull is a node’s 0-10 value
Barrier Type & Classes
1. Roads2. Active Railways3. Streams *4. Water bodies *
Barrier Type & Class make up 50% of the
Barrier Cost
* Aquatic Corridors are Special Cases
Road Barrier ClassesAssigned by Road Class
Highway = 100
Primary = 80
Local = 45
Service = 10
Dirt Roads = 5
Active Railway Barrier Classes
Assigned by Frequency & Speed
NE CORRIDOR = 100
OTHERS = 35
Ordered Streams & Waterbodies
All Waterbodies = 90
Barrier Classes for
by Stream Order
1-2 = 0
3-4 = 20
5-6 = 70
7+ = 90
Travel Cost by Type & Class
Relative Travel Cost
0
20
40
60
80
100
120
No
Bar
riers
Stre
am O
rder
1-3
Dirt
Roa
ds
Ser
vice
Roa
ds
Stre
am O
rder
4-5
Ram
ps/C
ul-d
e-S
ac/L
imite
d A
cces
sS
ervi
ce R
oads
Act
ive
Rai
lway
s
Stre
am O
rder
6
Loca
l/Nei
ghbo
rhoo
dR
oads
Wat
er b
odie
s
Stre
am O
rder
7
Sec
onda
ry/A
rteria
l
Prim
ary
Roa
d
Lim
ited
Acc
ess
Hig
hway
Nor
th E
ast C
orrid
or
Barrier
Cos
t
Combined Barriers
Barrier Density
1. Roads2. Active Railways3. Streams4. Waterbodies
Density makes up the remaining 50% of the
Barrier Cost
Barrier DensityBarrier Densitycalculation with 1,000m smoothing
Preliminary Cost Surface for Barriers
Modifying the Cost Surface
ConceptReducing the effect of Barrier Values (types/classes & density)based on :
1. The Conservation Values at each cell location
2. The proximity of Nodes and their ‘attractiveness value’ or ‘gravitational pull’at each cell location
+Modified Cost Surface -= (Barriers
NodeProximity
Conservation Value )
• Merged protected land sites with overlapping donut buffers of 1km and 2 km with values of 50% and 10 % respectively.
Node Proximity
Node ProximityProximity effect or
‘gravitational pull’ of Nodes
Modifying the Cost SurfaceSmooth
the cost surface by averaging across 10 cells (1000-ft)
so valuesacross the entire
RECOMMENDEDcorridor width are used to establish the least cost path
- not just the valueof one cell (100-ft)
_
SNOW PLOUGHvs
SNOW SHOVEL
3-Step Corridor Development Process
1. Developing the Cost Surface
2. Developing a Corridor Hierarchy
1. Aquatic Corridors * – To Be Added Manually Later
* Aquatic Corridors are Special Cases
Create a Network of Corridor Hierarchies Based on Node Size1. For each Node of a Specified Size Class, select all other
nodes within the Analysis Zone2. Generate Least Cost Path to each destination node across
the SMOOTHED (1000-ft averaging) Cost Surface3. Create a Cost Corridor (see explanation following)4. Generate Corridor Conservation Value where
• A = Source Node Conservation Value• B = Destination Node Values• Avg (A + B) = Corridor Value• & Avg (all cell values in corridor)
5. Repeat until all nodes within the analysis zone are linked to the Source Node
Regional Ecological Corridor Network
Regional Ecological Corridor Network
Concept - Corridor Network HierarchyEstablish corridors between connecting nodes of various sizes.
Network Hierarchy Node Size Search Radius #
Regional >1000 acres 20 miles 3
Sub-Regional >500 acres 8 miles 3
Local >250 acres 4 miles 3 ?
Cost Corridorexample -- Least Cost Path from Source to Destination Node
Cost CorridorCost Corridor between Source and Destination Node
• Corridor value diminishes across the cost surface
• NARROW = cost surface is high (barriers are high and /or conservation resources are low)
• BROAD =cost surface is low (barriers are low and/or conservation resources are high)
Cost CorridorCost Corridor between Source and Destination node
• Corridor value diminishes across the cost surface
• NARROW = cost surface is high (barriers are high and /or conservation resources are low)
• BROAD =cost surface is low (barriers are low and/or conservation resources are high)
Regional Ecological Corridor Network
1000-acre node & corridor results
1,000-acre Green Infrastructure
Regional Ecological Corridor Network
Complete Nodes & Corridors
Hierarchy
Regional Ecological Corridor NetworkFurther Work Required - Manual Upgrades & Refinements
1. Restoration Corridorssited where gaps in automated network considered too large biologically
2. Aquatic Corridors3. Substitution Recommendations - Potential Barrier Crossings
4. Prioritizing Nodes & Corridors
e.g. Least critical nodesbroadest cost corridor narrowest cost corridors
Most critical corridors w/1000ft buffer only
5. Rank Corridorsi. By number of times corridor selected between different nodesii. By corridor value
Uniqueness of this Approach• Uses a MODIFIED COST SURFACE
(i.e. Barriers - Conservation Values + Protected Lands value)
• RANKS PROTECTED LANDS by size, shape and ‘protectedness’ in standardized, relative classes, rather than just presence/absence.
• RANKS BARRIERS across landscape surface in standardized, relative classes rather than just presence/absence.
• RANKS CONSERVATION RESOURCES across landscape surface in standardized, relative classes rather than just presence/absence.
• Corridors selected by ENTIRE CORRIDOR WIDTH VALUES (1000 ft) - not just least costs path (snow plough vs snow shovel)
• Develops the concept of COST CORRIDORS
– so that practioners can see where they have flexibility when developing a corridor route, and where they have none.
SmartConservation ™
________________________________Building
Green InfrastructurePlans
For SE PennsylvaniaUsing ESRI Products
________________________________
Clare BillettNatural Lands Trust, Media, PA
_________________
www.natlands.org
www.smartconservation.org
http://cegs4.cas.psu.edu/scm
Funding provided by The William Penn Foundation
Pennsylvania Department of Conservation & Natural Resources