Book Image

Practical GIS

Book Image

Practical GIS

Overview of this book

The most commonly used GIS tools automate tasks that were historically done manually—compiling new maps by overlaying one on top of the other or physically cutting maps into pieces representing specific study areas, changing their projection, and getting meaningful results from the various layers by applying mathematical functions and operations. This book is an easy-to-follow guide to use the most matured open source GIS tools for these tasks. We’ll start by setting up the environment for the tools we use in the book. Then you will learn how to work with QGIS in order to generate useful spatial data. You will get to know the basics of queries, data management, and geoprocessing. After that, you will start to practice your knowledge on real-world examples. We will solve various types of geospatial analyses with various methods. We will start with basic GIS problems by imitating the work of an enthusiastic real estate agent, and continue with more advanced, but typical tasks by solving a decision problem. Finally, you will find out how to publish your data (and results) on the web. We will publish our data with QGIS Server and GeoServer, and create a basic web map with the API of the lightweight Leaflet web mapping library.
Table of Contents (22 chapters)
Title Page
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Dedication
Preface
14
Appendix

Chapter 4. Creating Digital Maps

In the previous chapters, we learned about data models, and how we can use them for our needs. In this chapter, we will learn about a new GIS concept--the representation model. The representation model applies different styles and styling rules to our raw data, and creates the styled result we see on our map canvas, and later, on our digital or printed maps. By styling our maps we can decide which properties of the data are important to the readers. For example, in a thematic map showing population, we don't need the road network, while we shouldn't make a road map unnecessarily complex with population data. We can also enhance readability by adding cartographic elements to our map, like a scale bar, a navigation grid, a legend, or a north arrow.

In this chapter, we will cover the following topics:

  • Styling raster and vector data
  • Using different projections
  • Using the print composer for creating spatial visualizations in QGIS
  • Creating real maps