An example application in

GIS ModelingPresentation and hands-on exercise materials prepared by

Joseph K. BerryKeck Scholar in Geosciences, University of Denver – Special Faculty in Natural Resources, Colorado State University

Principal, Berry & Associates // Spatial Information Systems

Email: jberry@innovativegis.com — Website: www.innovativegis.com/basis

Forest Availability and AccessibilityVast regions of the Rocky Mountains are under attack by mountain pine beetles and a blanket of brown is covering millions of

acres. Is there something we can do to contain the spread and hasten the regenerative cycle?

One suggestion is to remove the dead wood to speed forest health and convert it to useful products—but where and how much harvesting is appropriate?

Availability = fn (roads, forests, ownership, legal constraints)

Accessibility = fn (terrain, water, housing density, visual exposure)

…identify the best Landing Sites and characterize their Timbersheds

…for more information, see the online book Beyond Mapping III, Topic 29, Spatial Modeling in Natural Resources

www.innovativegis.com/basis/MapAnalysis/

http://summitvoice.files.wordpress.com/2010/01/pine-beetle-map.jpg http://earthtrends.wri.org/images/pine_beetle_dist.jpg

http://ndn1.newsweek.com/media/24/colorado-beetle-forest-destroy-wide-horizontal.jpg

Mountain Pine Beetle Devastation (Situation)

Vast regions of the Rocky Mountains are under attack by mountain

pine beetles.

Feller Buncher Skidder Wood Chipper

…but where and how much harvesting is environmentally,

economically and socially appropriate?

One possible action to help contain the spread of the beetles and improve

forest health is to remove the dead wood…

Forested areas are first assessed for Availability

considering ownership and sensitive area designation…

Sensitive AreasOwnershipRoads Forests

Forests and Roads

Slope Water Houses

…and then characterized by Relative Access considering intervening terrain factors of steepness and stream buffers, plus human factors of housing density and visual exposure to roads and houses.

Intervening Considerations

Assessing Forest Availability and Access (Fundamental considerations)

Forest Access Model

A map of Slope is used to establish relative and absolute barriers for operating mechanized harvesting equipment.

Maps of Ownership, Water, and Sensitive Areas are used to establish additional absolute barriers based on legal constraints.

Critical “ Map Variables” determining Accessible Forests locations

Forest Access Model (Flowchart)

Forests0 = not forested

1= forested Forest

Accessibility0 =road

to 120+ units away

AccumulationCost Surface

Relative Accessibility0 = road location

to 120+ units away

Discrete Cost Surface

UnavailableOwnerships = 0

Ownership

UnavailableSensitive = 0

Sensitive Areas

UnavailableWater Buffer = 0

Water

UnavailableToo Steep = 0

else assigned 1

Slope

Relative Steepness

1 = best:

9 = worst

Slope

Basic Access Model

Preference0 = no-go1 = best

:

9 = worst

Processing Flowchart

“EffectiveProximity”

40 Reach

0 1000 2000 ft

Simulation of different “reach scenarios” provides information on variations in wood supply from reaching deeper into the forest at increasingly higher access costs.

The inset on the right shows the forested areas that are much more easily accessed (40/120= .33 as far). Note the elimination of available forested locations (yellow to red) that are deemed

effectively “too far” from roads.

Basic Model Results (Effective proximity)

120 Reach

Not Available

Not Forested

Accessible Forests by Effective Proximity

Relative access values for all of the available forested locations with warmer tones indicating a long harvesting reach into the woods.

EffectivelyToo Far

Far

Far

Forests0 = not forested

1= forested Forest

Accessibility0 =road

to 120+ units away

Extended Model

Extended Model

…willing to reach farther into areas with low visual exposure and housing density

Multiplicative Weight

…willing to reach farther into areas with low visual exposure and housing density

Multiplicative Weight

Avg Weight

1 = High:

.7 = Medium:

.5 = Low

Ave

rag

e

Housing Density

0 = no housesto 66+ houses

Houses Sca

n HD Adjust1 = >50 High.7 = 20 to 50

.5 = 0 to 20 Low

HD Adjust1 = >50 High.7 = 20 to 50

.5 = 0 to 20 LowRen

um

ber

Extended Forest Access Model (Flowchart)

AccumulationCost Surface

Relative Accessibility0 = road location

to 120+ units away

Discrete Cost Surface

UnavailableOwnerships = 0

Ownership

UnavailableSensitive = 0

Sensitive Areas

UnavailableWater Buffer = 0

Water

UnavailableToo Steep = 0

else assigned 1

Slope

Relative Steepness

1 = best:

9 = worst

Slope

Basic Access Model (Physical and Legal concerns)

Preference0 = no-go1 = best

:

9 = worst

Visual Exposure

0 = not seento 344+ seen

Rad

iate VE Adjust

1 = >75 High.7 = 20 to 75

.5 = 0 to 20 Low

VE Adjust1 = >75 High.7 = 20 to 75

.5 = 0 to 20 LowRen

um

ber

Elevation

Extended Access Model (Human Concerns)

Roads

Houses

Co

mp

ute

Viewer Locations

Basic

Extended

Basic Model Results on the left-side indicates that the farthest away location is 116 effective distance units considering physical and legal barriers to access.

Comparison of Basic and Extended Model Results

Max = 116

Max = 116

Extended Model Results on the right-side indicates that the farthest away location is 76 effective distance units when considering the preference to harvest in

areas of low visual exposure and housing density.

Max = 76

Max = 76

Accessible Forest

Vegetation Type

Composite

2) Region-Wide Overlay

…there are 374 acres of accessible forest in Watershed 3

Accessible ForestData Map

WatershedsTemplate Map

Characterizing Accessible Forest Areas (Watershed area & timber types)

…there are 964 acres of accessible Lodgepole Pine

3) Location-Specific Overlay

Compute

Ren

um

ber

Accessible Forest

1) Create a Binary Map of Accessible Forests

Relative Access

Identifying Candidate Landing Sites (Gently sloped forest roads)

Stream_buffer

Protected

Unavailable

Forests

1) COMPUTE Roads times Forests times Unavailable times Protected times Stream_buffer for Forest_roads

Roads

Forest_Roads

The Forest_Roads map identifies road locations passing through available forest areas.

1

Slope

Forest_Roads

0 increasing steepness 65

2) SCAN Slope Average within 1 square around Forest_roads for Forest_roads_avgSlope

Roads_avgSlope

2

3) RENUMBER Forest_roads_avgSlope assign 1 to .01 thru 15 assign 0 to 15 thru 200 for Landing_candidates

The Landing_candidates map identifies road locations with gentle to moderate terrain (0-15% slope) within a 100 foot reach (~one acre) of a road that is accessible to available forested areas.

Landing_candidates

3

Landing_clumps

(#13, 159 paths)

(#9, 407 paths)

(#6, 155 paths)(#4, 56 paths)

(#2, 256 paths)(#5, 58 paths)

(#15, 785 paths)9

9) CLUMP Potential_landings Diagonally AT 1 FOR Landing_clumps

Locating the Best Landing Sites (High optimal path density)

6

OptimalPath_density

6) DRAIN Forests over Landing_accumulated_cost for OptimalPath_density

8) COMPUTE High_pathDensity Times Landing_candidates FOR Potential_landings

8

Landing _candidates

Potential_Landings

7) RENUMBER OptimalPath_density assign 0 to 0 thru 40 assign 1 to 40 thru 1000 for High_pathDensity

7

High_pathDensity

Discrete_cost

4) COMPUTE Discrete_cost Times Forests for Dcost_forests

4Dcostforests

5) SPREAD Landing_candidates to 200 THRU Dcost _forests Simply for Accum_proximity

The Accum_proximity map identifies the forest areas accessible from the Landing_Candidates as a continuous surface of effective distance.5

Accum_proximityLanding_candidates

The Landing_clumps map uniquely identifies the locations with the most accessible forests optimally connected

Services the largest number of accessible

forest locations

Services the largest number of accessible

forest locations

11) SPREAD Landings_best to 200 thru D_cost_forest simply for Landings_Accessible_forest

11

Landings_Accessible_forest

Identifying “Timbersheds” of the Best Landing Sites

10) RENUMBER Landing_clumps assign 0 to 1 assign 0 to 3 assign 0 to 7 thru 8 assign 0 to 10 thru 12 assign 0 to 14 assign 0 to 16 thru 50 for Landings_best 10

Landings_best

(#13, 159 paths)

(#9, 407 paths)

(#6, 155 paths)(#4, 56 paths)

(#2, 256 paths)

(#5, 58 paths)

(Landing #15, 785 paths)

12) RENUMBER Landings_Accessible_forest ASSIGNING -4 TO 80 THRU 200 FOR Timbersheds

Timbersheds

#13

#9#6

#4

#2

#5

Timbershed #15The Timbersheds map identifies all of the accessible forest locations that are “optimally” skidded to each of the Landing sites.

Timbershed #15740cells * .222ac/cell = 164 acres

…considering a practical reach of 80 effective cell lengths

…enabling technology used in spatial reasoning, dialog and decision-making—

GPS/GIS/RS

Geotechnology is one of the three "mega technologies" for the 21st century and promises to forever change how we conceptualize, utilize and visualize

spatial relationships in scientific research and commercial applications (U.S. Department of Labor)

Modeling involves analysis of spatial relationships

and patterns (Continuous/Numerical)

Prescriptive Modeling

Why and So What

Global Positioning System (location and navigation)

Remote Sensing(measure and classify)

Geographic Information Systems (map and analyze)

The Spatial Triad

(Nanotechnology) Geotechnology (Biotechnology)

Mapping involves precise

placement of physical features and inventories

(Discrete/Graphic)

Descriptive Mapping

Where is What

Map Analysis …provides “tools” for investigating spatial patterns and relationships

GeotechnologyGeotechnology – one of three “mega-technologies” for the 21st Century  

Global Positioning System (Location and navigation) Remote Sensing (Measure and classify) Geographic Information SystemsGeographic Information Systems (Map and analyze)

70s Computer Mapping (Automated cartography) 80s Spatial Database Management (Mapping and geo-query) 90s Map Analysis Map Analysis (Spatial relationships and patterns) 00s Multimedia Mapping (Spatial relationships and patterns)

A Logical Framework for Map Analysis

…for more information see www.innovativegis.com/basis/Papers/Other/GISmodelingFramework/

Spatial AnalysisSpatial Analysis (Geographic context)

Reclassify (single map layer; no new spatial information)Overlay (coincidence of two or more map layers; new spatial information)Proximity (simple/effective distance and connectivity; new spatial information)Neighbors (roving window summaries of local vicinity; new spatial information)   

Spatial StatisticsSpatial Statistics (Numeric context)

Surface Modeling (point data to continuous spatial distributions)Spatial Data Mining (interrelationships within and among maps)

Map Analysis Toolbox