Transcript An Introduction and Overview of ArcGIS 9.0

What Geoprocessing?
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Geoprocessing is the processing of
geographic information.
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Commonly used to describe a process
when geographic objects are manipulated
to create a new dataset.
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Many examples of geoprocessing…
Common Examples
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Buffer
Overlay analysis of vectors/rasters
Interpolation
Slope, Aspect from DEMs
Map/Grid algebra
Hydrologic analysis
Classification
Not-so-Common Examples
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Geocoding
Converting between file formats
Projecting
Select and export
Zonal statistics
Proximity analysis
Editing
What is Geoprocessing?
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So, it’s just about everything! Well, not
really…
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Geoprocessing is not: cartography, 2-D and
3-D symbolization, numerical statistics,
querys, labeling and annotation, GDB
schema, metadata
A few notes…
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Geoprocessing is just beginning in the 3-D
world and will likely increase.
Temporal modeling
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Significant improvements in 9.x
Incorporated into SA, ModelBuilder, 3-D
Solar radiation model into Framework
Process-oriented GIS (not by ESRI)
Geoprocessing in ArcGIS
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Focus on ArcGIS Desktop applications
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We’ll use ArcMap
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We’ll use ArcInfo Desktop
Geoprocessing Help
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ArcGIS Desktop online Help is the best place
to start.
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Overview of Geoprocessing
Tool reference and description
Command references
Examples in ModelBuilder and Scripting
ArcObject’s Developer Kit (VB, C++)
Geoprocessing Help
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PDFs in ESRI Library:
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Geoprocessing in ArcGIS
Geoprocessing Quick Reference Guide
Writing Geoprocessing Scripts
ESRI Support Center – Geoprocessing
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Scripts, Models, Docs, Forums
Five Ways to Work With Tools
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Command line
Dialogs
Models
Scripting
ArcObjects
Five Ways to Work With Tools
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Command line
Dialogs
Models
Scripting
ArcObjects
Intelligent Command Line
Command Line
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Command line window is aware of layers in
ArcMap session
Auto-complete and parameter options
Load and Save As from text files
Show History and Recall
Variables
Formatting of window
Five Ways to Work With Tools
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Command line
Dialogs
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ArcToolbox
Models
Scripting
ArcObjects
ArcToolbox Dialogs
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Most dialogs are aware of layers in ArcMap
session
Help available per parameter
Dialogs have link to environment settings
Easy to use
Five Ways to Work With Tools
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Command line
Dialogs
Models
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ModelBuilder
Scripting
ArcObjects
Five Ways to Work With Tools
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Command line
Dialogs
Models
Scripting
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Python, VBScript,
JavaScript
ArcObjects
Five Ways to Work With Tools
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Command line
Dialogs
Models
Scripting
ArcObjects
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VBA, VB, C++, C#
(COM)
ArcToolbox
ArcToolbox is now a dockable window
within ArcMap and ArcCatalog.
ArcToolbox
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Geoprocessing tools are available through
toolboxes or toolsets.
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Categorized by process type
Create your own toolboxes and tools
Full tool index and search functions
Locate tool function
Interface to ModelBuilder
Geoprocessing Wizard
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The ArcView 8.x Geoprocessing Wizard has
been removed from the ArcMap interface.
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However, the functions are still available just
located in separate toolsets.
Geoprocessing Wizard
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Dissolve— Data Management > Generalization >
Dissolve tool
Merge— Data Management > General > Append
tool
Clip— Analysis > Extract > Clip tool
Intersect— Analysis > Overlay > Intersect tool
Union— Analysis > Overlay > Union tool
Merge/Append
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Merge/Append operation – two or
more layers
Append adjacent layers
Appends data source(s) or
feature class(es) to an existing
Example:
Merge/Append several counties
Notice, when layers overlap:
Features are not intersected
Features and attributes are only
appended
Dissolve
Dissolve operation – one layer
process
􀂉 Aggregate features by value of
attribute when it is the same
􀂉 Creates new data source or
feature class
Example:
􀂉 Landuse Level 2 to Level 1
􀂉 Parcels based on ownership
Dissolve
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Dissolving features - simplify the data
based on common attribute values
Buffer
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Buffers are rings drawn
around features at a
distance
􀂉 By distance or
attribute value
􀂉 All features or only
selected features
􀂉 Outside, within,
multiple rings
􀂉 New layer or graphic
Clip
Clip operation – two layer process
􀂉 Reduce spatial extent of one layer
based on spatial extent of other
􀂉 Cookie cutter analogy
􀂉 Creates new data source or feature
class
􀂉 Same attribute table as input layer but
a subset
􀂉 Clip layer must be a polygon, input
layer any feature class
􀂉 Output layer feature class same as
input layer
Example:
􀂉 Limit area of geographic interest
􀂉 Only Ontario not all of Canada
Overlay Analysis / GeoProcessing
Overlay analysis functions
Intersect
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Intersect overlay – two layers necessary
􀂉 New layer with spatial extent only
common to two layers
􀂉 Attribute table inherits from both layers
􀂉 Creates new data source or feature class
􀂉 Input layer determines feature class for
output layer
􀂉 Overlay layer must be a polygon
Example:
􀂉 Intersection of Roads with several
counties
􀂉 Intersection of Pollution point with
counties
Union
Union overlay – two layers
necessary
􀂉 Combine two polygon feature
classes and only polygon feature
classes
􀂉 Attribute table inherits from both
layers
􀂉 Creates new data source or
polygon feature class
Example:
Soil layer with crop productivity
Union, example
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Find out influence of soil type over crop
productivity:
􀂉 Get a soils layer
􀂉 Get a crop productivity layer
􀂉 Use Union overlay to combine both layers in
one
􀂉 Query, Display, Analyze the new layer, based
on the new joint
attributes to determine if there is a relationship
between the
soil type and the crop productivity
Important!
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The output from the GeoProcessing
operation will be in the same coordinate
system as the Data Frame, irrespective of the
coordinate system of the data sources of the
input layers.
ArcMap Settings
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ArcMap
Tools
Options
Geoprocessing
ArcMap Settings
C:\ArcGIS\Utilities\AdvancedArcMapSettings.exe
Environment Settings
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Used by all geoprocessing tasks
Settings include:
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Workspace and mask
Coordinate system
Cell size and extent
Resampling method
Coverage and Geodatabase setting
etc…