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GIS Analysis Models

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Title: GIS Analysis Models


1
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GIS Analysis Models
3
GIS Analysis ModelGraphical modeling framework
tied to actual GIS functionsFunctions, Data,
Numerical Models, Tools, etc.
4
ArcGIS 9 Model Builder
5
ArcGIS 9 Model Builder
6
From Designing Gdbs - Ch 7Arc Hydro
HEC-RASHydrologic Engineering Centers River
Analysis System
See also Demo 2 from Apr 6 lecture
7
Arc Marine Model Builder
From Brett Lord-Castillo, M.S. thesis, and
Lord-Castillo et al., Transactions in GIS, in
review, 2009
8
Arc Marine Model Builder
Models to automatically extract environmental
data layers for spatio-temporal analysis
Model Get-SST
AML to Modeler conversion at ArcGIS 9.x
From Marine Data Model Technical Workshop, 2005
ESRI UC, Halpin et al.
9
The Anatomy of a GIS Analysis ModelBerry, Chs.
24-26
  • compare several GIS models to illustrate
    different analysis modeling approaches
  • compare varying levels of results from these
    models
  • GIS is only as good as its data
  • GIS is only as good the expression of its data

10
Its All Downhill from Here
  • the case for landslide susceptibility
  • terrain steepness (high slope/low slope)
  • soil type (unstable/stable)
  • vegetation cover (bare/abundant)

11
BINARY modelcodes cells 1 for susceptible0 for
unsusceptiblemultiplicative cells must meet all
3 criteria
12
BINARY modelmultiplies maps for Y/N
solutionRANKING modeladds maps for a range of
solutions
13
RATING modelaverages maps for an even greater
range of solutionsscale of 1 to 9 (most) for
each condition
14
RATING modelfor example one cell might be9 in
SL layer, 3 in SO, 3 in CO(9 3 3) / 3 5 or
moderate susc.
15
Weighted Rating Model
  • suppose SL is considered to be 5 times more
    important than SO or CO?
  • so one cell might be9 5 in SL layer, 3 in SO,
    3 in CO
  • ((95) 3 3) / 3 17
  • fairly high susc.

16
4 Models for Landslide SusceptibilityBanana
Bread to Fruit Cake!
  • BINARY
  • 1 for SL, 0 for SO, 0 for CO
  • 1 0 0 0 NO susceptibility
  • RANKING
  • 1 for SL, 0 for SO, 0 for CO
  • 1 0 0 1 LOW susceptibility
  • RATING
  • 9 for SL, 3 for SO, 3 for CO
  • (9 3 3) / 3 5 MODERATE susceptibility
  • WEIGHTED RATING
  • 9 for SL, 3 for SO, 3 for CO
  • ((95) 3 3) / 3 17 HIGH susceptibility

17
Banana Bread to Fruitcake
  • data input to the models - constant
  • logic of models or conceptual fabric of process -
    different
  • rating models most robust
  • continuum of responses/answers
  • foothold to extend model even further
  • from critical to contributing factors

18
Extension of Landslide Model to RiskConsider
Proximity to Features That we Really Care About
19
Extending a GIS Model ( cont. )
  • Risk
  • variable width road buffers as a function of
    SLOPE
  • buffer widens in steep areas
  • Extending hazard to risk
  • weighted roads based on slopes
  • weight roads based on traffic volume, emergency
    routes, etc.
  • buildings commercial, residential, etc.
  • economic value of threatened features, potential
    resource loss

20
Additional Factors
  • in addition to or instead of SL, SO, CO other
    critical factors may be considered
  • physical bedrock type, depth to faulting
  • disturbance construction areas, gophers?
  • environmental storm frequency, rainfall patterns
  • seasonal freezing and thawing cycles in spring
  • historical past earthquake events

21
Benthic Habitat ExampleParameters Important to
Benthic Species
  • Water depth
  • Sediment depth
  • Substrate type
  • Sediment type
  • Exposure
  • Rugosity/BPI
  • Slope/Aspect
  • Water chemistry
  • Water temperature
  • Voids/caverns (size depth)
  • Vegetation
  • Biotic interactions
  • Anthropogenic factors

What can we measure directly, interpret, or
derive?
Deidre Sullivan, MATE Center, Monterey, CA
22
Bathymetric grid created from multibeam x,y,z data
Monterey Bay data courtesy of MATE Center and
Cal-State Monterey Bay
23
Slope grid derived from bathymetry
24
Aspect grid derived from bathymetry
25
Rugosity grid derived from bathymetry using the
Benthic Terrain Modeler
Measure of surface area to planar area
26
Rugosity
  • Measure of how rough or bumpy a surface is, how
    convoluted and complex
  • Ratio of surface area to planar area

Surface area based on elevations of 8 neighbors
3D view of grid on the left
Center pts of 9 cells connected To make 8
triangles
Portions of 8 triangles overlapping center
cell used for surface area
Graphics courtesy of Jeff Jenness, Jenness
Enterprises, and Pat Iampietro, CSU-MB
27
Bathymetric Position Index (BPI)derived from
bathymetry using the Benthic Terrain
Modelerdusk.geo.orst.edu/djl/samoa/tools.html
28
Bathymetric Position Index(from TPI, Jones et
al., 2000 Weiss, 2001 Iampietro Kvitek, 2002)
Measure of where a point is in the overall land-
or seascape Compares elevation of cell to mean
elevation of neighborhood
29
Substrate type interpreted from Backscatter or
Side Scan Sonar images
30
Building a Suitability Model
  • What do we know about the species habitat
    requirements?
  • Can we describe these habitat requirements using
    GIS data?
  • Do we have enough information? Is it at the
    right scale?
  • Does the model work?

31
Validate the model

Benthic Terrain Modeler
Bathymetric Position Index
BPI
32
Using Standard Deviation to Classify Values
1
2
3
68 95 99
33
Binary Model(Multiplication)
1
0
0

1



Areas that satisfy both criteria
Rugosity greater than 1.2 SD
BPI greater than 1.5 SD
34
Ranking Model(Addition)
1
0
0
0
2

1

1


Ranking because it develops an ordinal scale of
increasing suitability
Rugosity is greater than 1.2 SD
BPI greater than 1.5 SD
35
Rating Model
Uses a consistent scale with more than two states
to characterize the habitat (simple average)


1
0
0
1
1
2
Rugosity is divided into 4 classes by SD then
reclassified to values of 1, 2, 3, 4
BPI is divided into 4 classes by SD then
reclassified to values of 1, 2, 3, 4
Rating because it develops a relative rating
based on the simple average of the factors
36
Uses a consistent scale with more than two states
to characterized the habitat, however it is a
weighted average
Weighted Rating Model
)
(


5
1
0
0
1
1
2
Rugosity is divided into 4 classes by SD then
reclassified to values of 1, 2, 3, 4
BPI is divided into 4 classes by SD then
reclassified to values of 1, 2, 3, 4
Weighted rating develops a relative ranking with
the most critical factors given more weight
37
How do they compare?
Ranking
Binary
Rating
Wt. Rating
38
Model Validation
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Mapematics
  • Rating models considered most mapematical
  • how were weighting factors decided?
  • guess-timates?
  • derived from predictive statistical technique?
  • need right set of maps/data over a large area
  • based on an experiment in the field?
  • lots of time, funding, energy
  • Review literature for existing mathematical model
    and make them mapematical (i.e., use them!)

41
GEO 580 ExamplePredicting presence of the
sensitive lichen Usnea longissima in managed
landscapesDylan Keon GEO 580 project
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Gateway to the Literature
  • Joerin, F., Using GIS and outranking
    multicriteria analysis for land-use suitability
    assessment, Int. J. Geog. Inf. Sci., 15 (2),
    153-174, 2001.
  • Jankowski, P., and T. Nyerges, GIS-supported
    collaborative decision making Results of an
    experiment, Annals AAG, 91 (1), 48-70, 2001.
  • Chau, K.T. et al., Landslide hazard for Hong Kong
    using landslide inventory and GIS, Computers
    Geosciences, 30 429-443, 204.
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