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Department of Civil Engineering
CIVL 1101 - GIS Quick Facts
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What is GIS?

Geographic Information Systems (GIS) provide a platform for displaying and analyzing spatial data.  GIS systems allow you to view multiple layers of data simultaneously.  GIS is a powerful tool for visualization, spatial analysis, and mapping.

Why is GIS important for engineers?

Engineers must make decisions regarding the possible alternative locations for a design and the impact of a particular decision, must model and analyze geographic data, and must communicate this information to various audiences.  GIS provides a way for engineers to overlay all of the data that is important to the decision, so that they can evaluate alternatives considering multiple factors.  GIS also provides a platform for spatial modeling.  GIS provides a visual tool for analyzing and presenting decision criteria.

Software

ArcGIS – GIS software platform created by ESRI.  We will be using ArcGIS exclusively this year.  ArcGIS contains several software applications, including ArcMap and ArcCatalog.

ArcMap – Mapping, editing, and analysis software within ArcGIS.

ArcCatalog – Data management software (create new files, manage database information, etc.) within ArcGIS.

Key Terminology

Project – This is a ‘session’ in ArcMap.  You can save a project so that you can return to the session and continue working.  The project will contain all datasets you imported, any maps you have created in the project, all symbology (the ‘look’ of your data) changes you have made, and any new data features you created through analysis.  When you save a project, it has a .mxd extension.

Feature Class – Data file containing a group of geographic data of the same type (point, line, or polygon). Feature Classes are contained within a geodatabase.

Shapefile – A single feature class.  These files can contain either point, line, or polygon data.  The shapefile is actually a collection of loose files when you look in the folder where you have saved the file.  It displays as a single .shp file when using GIS software.  The shapefile format is the format that ESRI shares in the public domain, and is used by other GIS software.

Geodatabase – A database for storing GIS data.  Think of a geodatabase as a ‘container’ for a group of related data.  You can have point, line, and polygon data all contained within a geodatabase as separate feature classes.  There are two types of geodatabases:

  • file geodatabase – can store large datasets and can be accessed by multiple users at a time; has .gdb extension

  • personal geodatabase – smaller datasets up to 2 GB, can only be accessed by one user at a time; has a .mdb extension.

Layer File – A file containing instructions for displaying a spatial data set (i.e. symbols, colors, etc.).  These files have a .lyr extension.

Attribute Table – A table containing data associated with your geographic files (shapefiles, feature classes).

Metadata – Descriptive information about your data.  This is entered and displayed in ArcCatalog.

 


This website was originally developed by Charles Camp for CIVL 1101.
This site is maintained by the Department of Civil Engineering at the University of Memphis.
Your comments and questions are welcomed.

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Department of Civil Engineering| 104 Engineering Science Bldg. |Memphis, TN 38152 | Phone: 901/678-2746 | Fax: 901/678-3026 | Last updated: 11/12/2021