Introduction to GIS using Open Source Software

Frank Donnelly, Geospatial Data Librarian, Baruch College CUNY

francis.donnelly@baruch.cuny.edu

Last Updated: August 15, 2011 (Version 2.0)

NOTE: This is an old version of this manual, written for QGIS 1.7. For the latest version (written for QGIS 1.8) go here.

This tutorial was created to accompany the GIS Practicum, a day-long workshop offered by the Newman Library at Baruch College CUNY that introduces participants to geographic information systems (GIS) using the open source software QGIS. The practicum introduces GIS as a concept for envisioning information and as a tool for conducting geographic analyses and creating maps. Participants learn how to navigate a GIS interface, how to prepare layers and conduct a basic geographic analysis, and how to create thematic maps.

This tutorial was written using QGIS version 1.7 "Wroclaw", a cross-platform (Windows, Mac, Linux) desktop GIS software package. Salient changes from previous versions (1.5 and 1.6) are noted in the text. You can download the software and user manual from the QGIS website at http://www.qgis.org/. The data used for the tutorial can be downloaded here or from the GIS Practicum page under the Tutorials and Courses tab on the Baruch GIS subject guide at http://guides.newman.baruch.cuny.edu/gis. Once you download and unzip the file, you'll see that the data files are separated into different folders for each part of the tutorial.

This tutorial and associated screenshots were created using QGIS in a Windows operating system. The names of certain tools and menus may vary slightly between operating systems, but functionality should be the same.

This document is divided into five parts and several subsections. Each subsection begins with steps for learning a specific application or process (the what and when), followed by commentary that explains various facets of the process (the how and why). The process and the commentary were separated in order to keep the steps as concise and easy to follow as possible with few digressions; you follow the steps first, and then go back and understand the details of why you followed the steps you did.

Objectives

Participants will be able to bring both the tools and the knowledge they gain from this workshop to enhance their projects and the organizations they work for. Specifically, this workshop will enable participants to:

Outline

Table of Contents

  1. An Overview of GIS
    1. Basic GIS Concepts
    2. GIS Software
    3. Open Source
  2. Exploring the Interface
    1. The QGIS Interface
      • Steps
      • Interface
    2. Adding Vector Data
      • Steps
      • Shapefiles
      • Adding Data to a Map View
      • Drawing Order
    3. Exploring the Map View
      • Steps
      • Measuring Distances and Areas
    4. Exploring Features
      • Steps
      • Attribute Tables
    5. Adding Raster Data
      • Steps
      • Raster Data
    6. Saving Your Project
      • Steps
      • Project Files
  3. Geographic Analysis
    1. Creating New Project from Existing One
      • Steps
      • Saving Projects and Removing Layers
    2. Geoprocessing Shapefiles
      • Steps
      • Geographic Units
      • TIGER Line Files
      • Geographic Selection
      • Geoprocessing
      • File Naming Conventions
    3. Joining and Mapping Attribute Data
      • Steps
      • Census Data
      • Identifiers
      • DBF Files
    4. Plotting Coordinate Data
      • Steps
      • Coordinate Data Sources
      • Delimited Text Files
    5. Running Statistics and Querying Attributes
      • Steps
      • Selection Criteria
      • Some Basic SQL
    6. Drawing Buffers and Making Selections
      • Steps
      • Buffers and Distance Measurement
      • File Management
      • Site Selection
    7. Screen Captures
      • Steps
      • Considerations and Next Steps
  4. Thematic Mapping
    1. Transforming Map Projections
      • Steps
      • Understanding Coordinate Reference Systems
      • Latitude and Longitude
      • Map Projections
      • GCS Definitions
      • Defining Undefined Projections
      • QGIS Projection Handling
    2. More Geoprocessing
      • Steps
      • Singlepart and Multipart Features
      • Generalization and Scale
      • CSV Files
    3. Creating Calculated Fields
      • Steps
      • Representing Values
      • Location Quotients
      • Industrial Classification: NAICS
    4. Classifying and Symbolizing Data
      • Steps
      • Data Classification and Color Schemes
      • Colorbrewer
    5. Designing Maps
      • Steps
      • QGIS Map Composer: Some Details
      • General Map Design
      • Output Formats
    6. Adding Labels
      • Steps
      • Labeling in QGIS
      • Thematic Maps and Symbols
      • Considerations and Next Steps
  5. Going Further
    1. Finding Data
    2. Data Sources
    3. Additional Concepts and Applications
  6. Appendix
    1. ID Codes
    2. Latitude and Longitude Distances
    3. Common CRS Definitions

Changes From Previous Manual

This manual (Version 2.0) has generally been updated from the previous version (Version 1.0) to reflect changes in QGIS software between versions 1.5 (Tethys) / 1.6 (Copiapo) and the latest version 1.7 (Wroclaw).

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