geog 409: advanced spatial analysis & modelling © j.m. piwowar1modelling essentials model...
TRANSCRIPT
© J.M. Piwowar 1Geog 409: Advanced Spatial Analysis & Modelling Modelling Essentials
Modelling Essentials
Model Parsimony
vs.
Model Simplicity.
© J.M. Piwowar 2Geog 409: Advanced Spatial Analysis & Modelling Modelling Essentials
Thinking Spatially
Begin by thinking about what your [spatial] output will be.You can then subdivide this spatial
information product into elements and operators.Recognize spatial patterns.Identify the processes that created the
patterns.
© J.M. Piwowar 3Geog 409: Advanced Spatial Analysis & Modelling Modelling Essentials
Visible Patterns
© J.M. Piwowar 4Geog 409: Advanced Spatial Analysis & Modelling Modelling Essentials
Visible Patterns
© J.M. Piwowar 5Geog 409: Advanced Spatial Analysis & Modelling Modelling Essentials
Visible Patterns
Measuring Visible Patterns - Landscape Metrics# of patches / areaPatch sizes & shapesPatch densities & inter-patch distancesIsolation metricsPerimeter-to-area ratiosOrientations
© J.M. Piwowar 6Geog 409: Advanced Spatial Analysis & Modelling Modelling Essentials
Functional Patterns
Not readily visible. Latent Patterns:
Threshold dependent
Temporally unique
© J.M. Piwowar 7Geog 409: Advanced Spatial Analysis & Modelling Modelling Essentials
Tools for Identifying Patterns
The LandscapeVisual observations by domain experts.
Not necessarily the same as the GIS modeller.
Observations should be made:At different times of the day;In different seasons;From different perspectives;With different viewing tools.
© J.M. Piwowar 8Geog 409: Advanced Spatial Analysis & Modelling Modelling Essentials
Tools for Identifying Patterns
Literature SurveysWithin-domain surveys.Extra-domain surveys.
Knowledge EngineeringDomain experts.Expert Systems.
© J.M. Piwowar 9Geog 409: Advanced Spatial Analysis & Modelling Modelling Essentials
Tools for Identifying Patterns
MapsVariations in themes, scales,
projections, perspectives, dimensionalities, symbolisms …
Aerial PhotographyVariations in tone, colour, texture,
setting, scale, association, time …
© J.M. Piwowar 10Geog 409: Advanced Spatial Analysis & Modelling Modelling Essentials
Tools for Identifying Patterns
Satellite ImageryVariations in spectral, spatial, temporal,
radiometric resolutions.Digital image analysis.
Statistical TechniquesDescriptive stats.Correlation, regression.Central tendency; spatial dispersion.
© J.M. Piwowar 11Geog 409: Advanced Spatial Analysis & Modelling Modelling Essentials
From Pattern to Process
Recognizing the spatial interactions of the problem
Sometimes determining the underlying processes that created the patterns; sometimes evaluating the effects of existing patterns on on-going processes.
© J.M. Piwowar 12Geog 409: Advanced Spatial Analysis & Modelling Modelling Essentials
From Pattern to Process
Go beyond pattern recognition into pattern description.
Dem
ers,
M.N
., 20
02.
GIS
Mod
elin
g in
Ras
ter.
Wile
y.
© J.M. Piwowar 13Geog 409: Advanced Spatial Analysis & Modelling Modelling Essentials
Types of GIS Models
Purpose ModelsDescriptive Models
Describe parts or all of a study area.Passive.E.g. a map.
Prescriptive ModelsPrescribe best solutions.Active.E.g. best location analysis
© J.M. Piwowar 14Geog 409: Advanced Spatial Analysis & Modelling Modelling Essentials
Types of GIS Models
Methodological ModelsDeterministicStochastic
Logistic ModelsInductiveDeductive