Welcome to DEP’s GIS Workshop Series Workshop 2: GIS Data and File Types 1

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. 2 GIS 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. 3 GIS File Types in DEP

4 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. 5 GIS File Types in DEP

GIS File Types Coverages Shapefiles (.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) 6

Coverages Old format Used in ArcView 3 and earlier versions No longer editable in ArcGIS 9.3, but can be displayed Cumbersome File Storage Can include export files (.e00 file extension) GIS File Types in DEP 7

Coverages GIS File Types in DEP 8 Export Files Coverage Files

Shapefiles Has 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

10 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 Geodatabases Is 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 files Is meant for large amounts of data Is very fast at data retrieval Is more efficient than a personal geodatabase Is a new file type, not yet well known or used. GIS File Types in DEP 13

ArcSDE Data Stands 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 15 GIS 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 17 GIS 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 Files Vs. 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 Open ArcCatalog 2. 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.? 1. ____________________________________ 2. ____________________________________ 3. ____________________________________ 4. ____________________________________

Class Exercise - Answers GIS File Types in DEP File geodatabase “Habitat.gdb” 2. Personal geodatabase “Statewide_Trails.mdb” 3. Layer file “Connecticut_Town.lyr” 4. Shapefile “Dam.shp”

End of Workshop 2 22