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 8. Spatial Analysis in QGIS

In the previous chapter, we learned how spatial RDBMSs work on the example of PostGIS. We went through the typical data types, tables, views, functions, and other objects, while also discussing how we can construct a great spatial database, which can effectively enhance our work. Now that we can ease our job by using spatial databases, we will move on and learn about spatial analysis. To have a full-blown example on which we can work, let's assume we are very enthusiastic real estate agents. We are happy to go that extra mile to please our customers who have very specific conditions on their dream houses. The price and size of the house does not matter in this case, although its situation must meet certain criteria.

In this chapter, we will cover the following topics:

  • Vector analysis
  • Building models in QGIS
  • Digital elevation models (DEM)
  • Using GRASS from QGIS