Models and Structures of ArcGIS UML and Data Modeling Elements.

Models and Structures of ArcGIS

UML and Data Modeling

Elements

Model / Data Model• Model = representation of something in

the real world, of a process in the real world - how the world WORKS

• Data Model = representation of data or information ABOUT that something or process - how the world LOOKS– limited representation of reality

• a discretization or partitioning of space• constructs for representation in a computer

Data Model

• usually a representation of the data collection process

• FIELD … “grid”• OBJECT … “isoline”• FIELD or OBJECT … “geo-relational” • “Delauney triangulation” (alternative)

• partition areas based on “influence” of sample points (Thiessen polys)

e.g., trusted elevation benchmarks or VIPs, market area delimitation, rain gauge area assignment, etc.

3 Data Models

• geo-relational coverage (object view; from classic ArcInfo)

• geo-relational shapefile (object view; from ArcView)

• geodatabase (object-oriented; from ArcGIS)

A

B

command line interfaceUnix, NT, WindowsArcView as interface

Georelational Data Model:“Classic” ArcInfo and ArcView

Data Structure• the way in which the data model is represented

in the GIS• concerned simply with what can be computed

and what can’t• not tied to process at all• DEM/raster for field model• coverage/shapefile for ESRI geo-relational

(object model)• contour for isoline variation on object model• TIN for Delauney triangulation/Voronoi model• geodatabase for OO geodatabase

Data Structures

• ArcInfo coverages• ArcView shapefiles• ArcInfo grids, USGS DEMs • Images (e.g., georeferenced tiffs)• TINs• Geodatabases

ESRI Coverage as a Data Structure

Image courtesy of Louisville/Jefferson County Information Consortium, Kentucky

ESRI “Shapefile”.shp — shape format; the feature geometry itself.shx — shape index format; a positional index of the feature geometry to allow seeking forwards and backwards quickly.dbf — attribute format; columnar attributes for each shape, in dBase III format

.prj — projection format; the coordinate system and projection information, a plain text file describing the projection.sbn and .sbx – spatial index.xml — metadata in XML format

ArcGIS Icons( Zeiler, pp. 65-71 )

yellow coverage

gray geodatabase

green shapefile

Geodatabase

If coverages are apples …

and shapefiles are oranges …

The Geodatabase can be your grocery bag…

ESRI Geodatabase Video (3:57 to 11:20)

Elements of the Geodatabase

• Feature Datasets• Feature Classes• Relationship classes• Geometric Networks• Domains• Ranges• Coded Values• Topology• Tables• Metadata• And More!!!

Geodatabase

• Features and attributes as objects

• Relationships among features

• Validation or editing rules, behaviors

• “Container” for– Vector, raster, tabular

data

– Relationships

– Topology

MS-Office

Object Table

Relationships for a feature

Sharing on Steroids:ESRI Data Models for Geodatabase

TemplatesPre-designed schema (skeleton) of• Objects

-Feature classes-Tables

• Relationships• Domains• Rules

Why Data Models & Gdb Templates?

• Work with users & partners on practical design projects

• Build useful ready to load geodatabases• Continue the process with feedback from

real projects• Support & encourage standards

ArcGIS Data ModelsAdministrative BoundariesAgricultureBasemapBiodiversity/ConservationCadastre 2014Defense/IntelEnergy UtilitiesEnvironmental Regulated FacilitiesHistoric PreservationHydrographic/Navigation (IHO)

Local GovernmentMarinePetroleumPipelineSystem ArchitectureTelecommunicationsTransportationWater UtilitiesWater Resources (Hydro, Groundwater)ForestryGeologyLand Parcels

http://support.esri.com/datamodels

Arc Marine dusk.geo.orst.edu/djl/arcgis

Data Modeling for Spatial Analysis

• What is spatial analysis?– "a set of methods whose results change when the

locations of the objects being analyzed change"

• Methods for working with spatial data – to detect patterns, anomalies– to find answers to questions – to test or confirm theories

• deductive reasoning

– to generate new theories and generalizations• Inductive reasoning

What is Spatial Analysis (cont.)

• Methods for adding value to data – in doing scientific research

– in trying to convince others

• A collaboration between human and machine

• How do we set up the framework for spatial analysis? – Data model to data structure

A Georelational to a Geodatabase Model

• coverage and shapefile data structures– homogenous collections of points, lines, and

polygons with generic, 1- and 2-dimensional "behavior"

• can’t distinguish behaviors– Point for a marker buoy, same as point for OBS

• “smart features” in a geodatabase– lighthouse must be on land, marine mammal

siting must be in ocean

• basic template for implementing GIS projects– input, formatting, geoprocessing, creating maps,

performing analyses

• basic framework for writing program code and maintaining applications– development of tools for the community

• promote networking and data sharing through established standards

Purpose of Arc Marine, Arc Hydro and others

Arc Marine Design Strategy

“Generic”

Marine Data Model

User Group

Data Model

User Group

Data Model

User Group

Data Model

Project

Data Model

Project

Data Model

Project

Data Model

Inh

erit

ance

Geodatabase Concepts• ESRI's new data object-oriented data model

– objects, features, behaviors• Geodatabase

– collection of feature classes/data sets, rasters, TINs– all data in relational tables – behavior is coupled with features through rules (object-orientation)

• Feature data set– Contains feature classes – defines topological role of features

– has a coordinate system

• Feature class– stored in a relational table– special field for geometric shape – geometric data incorporated into the database

• Point, multipoint, segment, path, ring, polyline, polygon

Geodatabase Feature Class Geometries

ArcMarine GeodatabaseOverall Geodatabase

Feature Dataset

FeatureClass

Table

RelationshipClass

Real World Objects and relationships

DatabaseSchema

(Object state)

(3) Physical Model

Modeling Process(1) Conceptual ModelLists, flow diagrams, etc

(2) Logical ModelDiagram in CASE

Tool

Graphic courtesy of ESRI

Data Model Levels

IncreasingAbstraction

RealityReality

Conceptual ModelConceptual Model

Logical ModelLogical Model

Physical ModelPhysical Model

Human-oriented

Computer-oriented

(1) Conceptual - User’s View of Data

Conceptual - cont.

(2) Logical - UML

• Unified Modeling Language

• Diagrammatic notation = “visual language”...

• For constructing a data model• Drawings, relationships constructed in

Visio• Tools to input a drawing to ArcGIS

– input data to the data model

From (1) Conceptual

To (2) Logical

UML NotationZeiler pp. 97-99

• a class is shown as a box

• top part: name of class

• lower part: attributes

• methods associated with the class

• lines connect boxes, indicate relationships

Graphic courtesy of Maidment et al., ArcHydro team

UML Notation ( cont. )

• Abstract class – specify subclasses

underneath– no new instances

• Feature Class– Specify subtypes

underneath

Food

VeggiesMeats

Relationships

• Links between classes, shown as lines

• One to one

• One to many

• Many to many

Relationships (cont.)

• 1:1 - solid line– one record in Class A linked to one record in

Class B• “is married to”• the class of state capitals linked to the class of

states

• 1:n - solid line with * at one end– one record in Class A linked to any number of

records in Class B• "owns" • the class of states linked to the class of area codes

Relationships (Arc Marine example)

Relationships (cont.)

• m:n - solid line with * at both ends– any number of records in Class A linked to any

number of records in Class B• "has visited”• "was never married to" • the class of mountain lions linked to the class of

wilderness areas

Relationships

Type Inheritance

• White triangle– Class B inherits the

properties (attributes, methods) of Class A

– the class street inherits from the class transportation network

• Solid diamond

– the parts and the whole depend on each other

lecture lab


DatabaseSchema

(Object state)

(3) Physical Model



Tool


or XMI file

(3) Physical

Using a Design TemplateSchema Wizard reads repository or XMI

to create a geodatabase

or XMI file

(3) Physical

Data Model Levels

IncreasingAbstraction

RealityReality

Conceptual ModelConceptual Model

Logical ModelLogical Model

Physical ModelPhysical Model

Human-oriented

Computer-oriented


DatabaseSchema

(Object state)

(3) Physical Model



Tool


Arc Marine Data Model Exercise

• Exercise and data at dusk.geo.orst.edu/djl/arcgis/ArcMarine_Tutorial/

• What to turn in:– Screen snapshot of what your ArcMap session looks like

at the end of Section 4 (including dynseg referencing)

– Answers to 2 simple questions at end of Section 4 (which cruise? which vehicle?)

– Can put all of the above in a single MS-Word document, labeled with your NAME please!

• Due by email or dropbox, April 27th, 6:00 p.m.

Geoprocessing Models Model Builder diagrams for workflow

Raster in

WGS84

extract_west Shifted_west

Output

grid name

Extract_east

Raster in

WGS84

Extract by

Rectangle (2)Output

Extent

Output

Extent

Output

Extent

Shift

Extract by

Rectangle (3)

Extract by

Rectangle

Mosaic

Output

Extent

Use of a Data Model in an Analysis Model

Model Builder geoprocessing diagrams for workflow

Gateway to the Literature• Arctur, D. and Zeiler, M., 2004, Designing

Geodatabases, ESRI Press• Lowe, J.W., 2003. Flexible data models strut the runway.

Geospatial Solutions, 13(2): 44-47.• Maidment, D.R., 2002. Arc Hydro: GIS for Water

Resources, ESRI Press, 203 pp. w/CD.• Li, X. and M.E. Hodgson, 2004. Vector-field data model

and operations. GISci. Rem. Sens., 41(1): 1-24.

• Wright, D., Blongewicz, M., Halpin, P., and Breman, J., Arc Marine: GIS for a Blue Planet, Redlands: ESRI Press, 2007. – In Digital Earth or dusk.geo.orst.edu/djl/arcgis/book.html

Objects and Features

• Object (real world)– in ArcGIS an object is non-spatial

– it is NOT a point, line, or area

– it has no geographic location

– it has no shape attribute in its table

– Drainage network, ship, vehicle, … customer, lake, house, etc.

• Feature (spatial context)– an object that has geographic location

– a point, line, area, TIN, raster

Models and Structures of ArcGIS UML and Data Modeling Elements.

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