unit ten: geoprocessing
DESCRIPTION
Unit Ten: Geoprocessing. What is Geoprocessing? Geoprocessing examples ArcToolbox Basics Append (formerly ‘merge’) Clip Buffer Join by Location. In this unit…. Geoprocessing is…. The use of a computer to model interpret alter or create data, - PowerPoint PPT PresentationTRANSCRIPT
Unit Ten: GeoprocessingUnit Ten: GeoprocessingIn this unit…In this unit…
What is Geoprocessing?What is Geoprocessing?
Geoprocessing examplesGeoprocessing examples
ArcToolbox BasicsArcToolbox Basics
Append Append (formerly ‘merge’)(formerly ‘merge’)
ClipClip
BufferBuffer
Join by LocationJoin by Location
2Unit Ten – GeoprocessingUnit Ten – Geoprocessing
The use of a computer to The use of a computer to
modelmodel interpretinterpret alter oralter or
create data, create data, through the application of geospatial through the application of geospatial
relationships.relationships.
Geoprocessing is…Geoprocessing is…
3Unit Ten – GeoprocessingUnit Ten – Geoprocessing
Geoprocessing ExamplesGeoprocessing Examples
► Create a new data setCreate a new data set showing blocks of land unfragmented by roads, showing blocks of land unfragmented by roads, rank by sizerank by size
► Identify distance Identify distance along a road network along a road network from fire hydrants and ponds to structures from fire hydrants and ponds to structures rank by distancerank by distance
► Locate Locate development that is within 100 feet of prime wetlandsdevelopment that is within 100 feet of prime wetlands select the featuresselect the features
4Unit Ten – GeoprocessingUnit Ten – Geoprocessing
ArcToolbox BasicsArcToolbox Basics
What’s a “Tool”?What’s a “Tool”?► A “wizard” utility that A “wizard” utility that
walks you through the walks you through the steps and data needed steps and data needed to accomplish a task.to accomplish a task.
► A source of context A source of context sensitive help.sensitive help.
Geoprocessing functions are found in ArcToolBox Geoprocessing functions are found in ArcToolBox “tools”.“tools”.
““Input Features” = data to act uponInput Features” = data to act upon““Output Feature Class” = where results Output Feature Class” = where results
gogo
5Unit Ten – GeoprocessingUnit Ten – Geoprocessing
► Some ArcToolBox functions create the Some ArcToolBox functions create the “Output Feature Class” you ask for… “Output Feature Class” you ask for…
► Drag & drop files from ArcMap:Drag & drop files from ArcMap:
because it’s fasterbecause it’s faster
to tell ArcToolbox tools to act only on to tell ArcToolbox tools to act only on features selected in the map document. features selected in the map document.
to refresh ArcToolbox’s awareness of to refresh ArcToolbox’s awareness of newly created files (“empty” files).newly created files (“empty” files).
► When you see an error icon, you can When you see an error icon, you can “flyover” with the cursor to see a message“flyover” with the cursor to see a messagethat describes why your function is about that describes why your function is about to fail!to fail!
ArcToolbox BasicsArcToolbox Basics
Means
we
Means
we
need a
n “
em
pty
file
”
need a
n “
em
pty
file
”
……dra
gged f
rom
dra
gged f
rom
Arc
Map o
r A
rcCata
log
Arc
Map o
r A
rcCata
log
……others require you to create a new others require you to create a new “empty” file. Look for the error. “empty” file. Look for the error.
6Unit Ten – GeoprocessingUnit Ten – Geoprocessing
ArcToolbox BasicsArcToolbox Basics► Launching ArcToolbox…Launching ArcToolbox…
……into the ArcMap environment makes it into the ArcMap environment makes it sensitive to feature selections, or…sensitive to feature selections, or…
……in stand-alone mode from within ArcCatalog in stand-alone mode from within ArcCatalog where it acts on where it acts on allall featuresfeatures regardless of which regardless of which features may be selected in map documents.features may be selected in map documents.
7Unit Ten – GeoprocessingUnit Ten – Geoprocessing
ArcToolbox BasicsArcToolbox Basics► Toolbox organization is not always easy to remember.Toolbox organization is not always easy to remember.
► Search & Index tabs can help locate tools. Search & Index tabs can help locate tools.
► Index: Has type-ahead feature requiring exact match of tool Index: Has type-ahead feature requiring exact match of tool namename((LOCATELOCATE button goes directly to the tool). button goes directly to the tool).
Gets Gets nothing…nothing…
Finds as Finds as you type.you type.
► Search: for general Search: for general searches when you searches when you aren’t sure of the tool’s aren’t sure of the tool’s name.name.
► Or… use the general Or… use the general ArcGIS Help Search.ArcGIS Help Search.
8Unit Ten – GeoprocessingUnit Ten – Geoprocessing
AppendAppend – a “stitcher” – a “stitcher”
► A basic “A basic “Merge”Merge” application: Stitching together application: Stitching together data delivered in “quad-sized” packages.data delivered in “quad-sized” packages.
► Example: four packages (layers) of data:Example: four packages (layers) of data: Each file is the size of a Each file is the size of a
7.5 minute quadrangle7.5 minute quadrangle
Each was created to Each was created to “edge-match” with the other.“edge-match” with the other.
After a successful merge: a After a successful merge: a single file with the data structuresingle file with the data structure(fields) of one of the files(fields) of one of the files
11 22
33 44
7.5 min7.5 minquadquad
9Unit Ten – GeoprocessingUnit Ten – Geoprocessing
AppendAppend – Field Selection – Field Selection
► TEST Schema Type: because we expect fields to be the TEST Schema Type: because we expect fields to be the same in both datasets same in both datasets (i.e. matching the Output Features)(i.e. matching the Output Features)
► NO_TEST Schema Type: because sometimes they aren’t NO_TEST Schema Type: because sometimes they aren’t (the same in both datasets)(the same in both datasets)
fieldsfieldsfieldsfields FIDFID NamNamee
StatStatee
CountCountyy
FIDFID NamNamee
StatStatee
CountCountyy
FIDFID CountyCountyFIDFIDNameName NameNameSTST CTYCTY StateState
10Unit Ten – GeoprocessingUnit Ten – Geoprocessing
ClipClip – a “cookie-cutter” – a “cookie-cutter”
► A basic “A basic “ClipClip” application: create a subset ” application: create a subset of data from state-wide data that “stops” of data from state-wide data that “stops” at the boundaries of a town.at the boundaries of a town.
► The state-wide data is the “dough”The state-wide data is the “dough”
► The boundaries of the town The boundaries of the town is a cookie cutteris a cookie cutter
RESULTRESULT
11Unit Ten – GeoprocessingUnit Ten – Geoprocessing
BufferBuffer
► A basic “A basic “BufferBuffer” application: establish a ” application: establish a riparian habitat buffer along waterwaysriparian habitat buffer along waterways
► Select the features (if needed)Select the features (if needed)
► Determine the buffer distanceDetermine the buffer distance►From entryFrom entry►From a field in the dataFrom a field in the data►As multiple “rings”As multiple “rings”
► Create as:Create as:►GraphicGraphic►New fileNew file► In existing fileIn existing file
12Unit Ten – GeoprocessingUnit Ten – Geoprocessing
Join Data by Location ToolJoin Data by Location Tool
How does it How does it work?work? Join any of
Join any of
these features…these features…
That are within That are within
these features…these features…
Result!Result!
(sort of)(sort of)
Source LayerSource Layer
Target LayerTarget Layer
13Unit Ten – GeoprocessingUnit Ten – Geoprocessing
Join Data by Location ToolJoin Data by Location Tool
What do you get?What do you get?
FIDFID NameName StateState CountyCounty ptFlptFl
dd ptFldptFld ptFldptFld ptFldptFld
No matchNo match
► No change to the graphical No change to the graphical appearance of the data… this is an appearance of the data… this is an ATTRIBUTE joinATTRIBUTE join
► New columns New columns (a.k.a. fields)(a.k.a. fields) are added to the attribute are added to the attribute table of the target layertable of the target layer
xxxxxx
14Unit Ten – GeoprocessingUnit Ten – Geoprocessing
Your turn…Your turn…
Chapter 10: Step 1 through ENDChapter 10: Step 1 through END
SAVE OFTEN!SAVE OFTEN!