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

_________________

cbillett@natlands.org

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