Welcome to Welcome to DEP’s GIS Workshop DEP’s GIS Workshop
SeriesSeries
Workshop 2: GIS Data and File Types
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Explanation of Some GIS Terms
Spatial Data – any data that can be represented as a location on the face of the Earth.
GIS – Geographic Information System - is any system for capturing, storing, analyzing and managing data and associated attributes which are spatially referenced to Earth.
2GIS File Types in DEP
Explanation of Some GIS Terms
Vector Data – Data that contains individual features such as rivers, lakes, roads, soils, aquifer protection areas, dam sites. Also known as feature data.
Raster Data – Data that is just a “picture” and contains no information about individual features. For example, the topo maps are raster data. There is no information about individual features such as rivers, lakes, etc. other than what is viewed in the “picture”. Also known as image data.
3GIS File Types in DEP
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Explanation of Some GIS Terms
Points – That spatial data type that consists only of points, or locations, on a map. An example is dam locations in Connecticut.
Lines – That spatial data type that consists only of lines
on a map. An example is roads.
Polygons – That spatial data type that consists only of areas on a map. An example is DEP state parks parcels.
GIS File Types in DEP
Explanation of Some GIS Terms
Feature Class, Dataset, Datalayer – These are all terms that refer to one “layer” of data on a map. For example, the feature class “Named Waterbodies” contains only waterbodies. The feature class “Soils” contains only soil areas. The feature class “Dams” contains only points on the map where dams are located.
Rasters or images are also considered datalayers. For example, the USGS Topographic Quadrangle Maps is a datalayer.
5GIS File Types in DEP
GIS File TypesCoveragesShapefiles (.shp)Raster or Image Data (.tif, .sid, .jpg, .bmp,
etc.)Personal Geodatabases (.mdb – same as
an Access database)File Geodatabases (.gdb)ArcSDE Databases (best accessed through
layer files)
GIS File Types in DEP 6
Coverages
Old formatUsed in ArcView 3 and earlier versionsNo longer editable in ArcGIS 9.3, but can be
displayedCumbersome File StorageCan include export files (.e00 file extension)
GIS File Types in DEP 7
Coverages
GIS File Types in DEP 8
Export Files
Coverage Files
ShapefilesHas become a worldwide standard for GIS
data
Can be displayed and edited in ArcGIS 9.3 and in all earlier versions of ArcView.
Has multiple files for storage; can be cumbersome. For example, all of these files as viewed in Windows Explorer make up one shapefile: Town.shp, Town.shx, Town.sbx, Town.sbn, Town.prj, Town.dbf
Using the Desktop Administrator and GIS File Types in DEP 9
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Aquifer Protection Area Shapefiles
Using the Desktop Administrator and GIS File Types in DEP
Raster or Image Files
Using the Desktop Administrator and GIS File Types in DEP 11
• Raster Files do not have identifiable
or editable features
• Many types of raster (image) files
can be used in ArcGIS:
.tif, .jpg, .png, .gif, .bmp, .sid, .dwg
Personal GeodatabasesIs an Access Database (.mdb file)
All spatial data and tables reside in one file
Easy storage format
Topology can be used for spatial accuracy
Can contain multiple types of data (tables,
feature classes, layers, rasters, etc.)
Maximum file size: 2 gb
Using the Desktop Administrator and GIS File Types in DEP 12
File Geodatabases
Data stored in a folder with an extension of “.gdb”.
Contains a number of filesIs meant for large amounts of dataIs very fast at data retrievalIs more efficient than a personal geodatabaseIs a new file type, not yet well known or used.
GIS File Types in DEP 13
ArcSDE DataStands for Spatial Data Engine
Managing spatial data and relational
databases with large amounts of data
Is the future of GIS data in DEP
Most efficient for large organizations
Can support multi-user editing
Works with SQL, Oracle
GIS File Types in DEP 14
Example of ArcSDE Files
15GIS File Types in DEP
What are Layer Files?Characterized by “.lyr”.
Does not contain actual spatial or attribute
data, only “points to” data
Determines symbology, scale levels, table
view, data view
Can have multiple datasets in one layer
Easy to use – just add one .lyr file
GIS File Types in DEP 16
Example of Layer Files
17GIS File Types in DEP
What is the R: Drive?
Central repository for all GIS data
Contains all file types that exist for a datalayer
Will soon be replaced by a different GIS storage area on the Y: Drive
GIS File Types in DEP 18
Chart of R: Drive FilesVs. ArcSDE Files
Navigate to C:\ArcGIS_Training\Class2\
Open the following file:Rdrive_and_SDE_Layers.pdf
This is a list of the old R: drive files and their corresponding files in SDE
GIS File Types in DEP 19
Class Exercise
GIS File Types in DEP 20
1. Open ArcCatalog2. Navigate to the following folder:
\My Documents\Class2\GISFiles\3. What types of GIS files do you see in this folder,
i.e. shapefiles, SDE files, coverages, layer files, file/personal geodatabases, etc.?
4. ____________________________________5. ____________________________________6. ____________________________________7. ____________________________________
Class Exercise - Answers
GIS File Types in DEP 21
1. File geodatabase “Habitat.gdb”2. Personal geodatabase “Statewide_Trails.mdb”3. Layer file “Connecticut_Town.lyr”4. Shapefile “Dam.shp”
End of Workshop 2End of Workshop 2
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