What Geoprocessing? Geoprocessing is the processing of geographic information. Commonly used to describe a process when geographic objects are manipulated to create a new dataset. Many examples of geoprocessing…

Common Examples Buffer Overlay analysis of vectors/rasters Interpolation Slope, Aspect from DEMs Map/Grid algebra Hydrologic analysis Classification

Not-so-Common Examples Geocoding Converting between file formats Projecting Select and export Zonal statistics Proximity analysis Editing

What is Geoprocessing? So, it’s just about everything! Well, not really… Geoprocessing is not: cartography, 2-D and 3-D symbolization, numerical statistics, querys, labeling and annotation, GDB schema, metadata

A few notes… Geoprocessing is just beginning in the 3-D world and will likely increase. Temporal modeling  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 Focus on ArcGIS Desktop applications We’ll use ArcMap We’ll use ArcInfo Desktop

Geoprocessing Help ArcGIS Desktop online Help is the best place to start.  Overview of Geoprocessing  Tool reference and description  Command references  Examples in ModelBuilder and Scripting  ArcObject’s Developer Kit (VB, C++)

Geoprocessing Help PDFs in ESRI Library:  Geoprocessing in ArcGIS  Geoprocessing Quick Reference Guide  Writing Geoprocessing Scripts ESRI Support Center – Geoprocessing  Scripts, Models, Docs, Forums

Five Ways to Work With Tools Command line Dialogs Models Scripting ArcObjects

Five Ways to Work With Tools Command line Dialogs Models Scripting ArcObjects Intelligent Command Line

Command Line 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 Command line Dialogs  ArcToolbox Models Scripting ArcObjects

ArcToolbox Dialogs 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 Command line Dialogs Models  ModelBuilder Scripting ArcObjects

Five Ways to Work With Tools Command line Dialogs Models Scripting  Python, VBScript, JavaScript ArcObjects

Five Ways to Work With Tools Command line Dialogs Models Scripting ArcObjects  VBA, VB, C++, C# (COM)

ArcToolbox ArcToolbox is now a dockable window within ArcMap and ArcCatalog.

ArcToolbox Geoprocessing tools are available through toolboxes or toolsets.  Categorized by process type  Create your own toolboxes and tools Full tool index and search functions Locate tool function Interface to ModelBuilder

Geoprocessing Wizard The ArcView 8.x Geoprocessing Wizard has been removed from the ArcMap interface. However, the functions are still available just located in separate toolsets.

Geoprocessing Wizard Dissolve— Data Management > Generalization > Dissolve toolData Management > Generalization > Dissolve tool Merge— Data Management > General > Append toolData Management > General > Append tool Clip— Analysis > Extract > Clip toolAnalysis > Extract > Clip tool Intersect— Analysis > Overlay > Intersect toolAnalysis > Overlay > Intersect tool Union— Analysis > Overlay > Union toolAnalysis > Overlay > Union tool

Merge/Append 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 Dissolving features - simplify the data based on common attribute values

Buffer 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 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 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! 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 ArcMap Tools Options Geoprocessing

ArcMap Settings C:\ArcGIS\Utilities\AdvancedArcMapSettings.exe

Environment Settings Used by all geoprocessing tasks Settings include:  Workspace and mask  Coordinate system  Cell size and extent  Resampling method  Coverage and Geodatabase setting  etc…