Book Image

QGIS 2 Cookbook

By : Alex Mandel, Víctor Olaya Ferrero, Anita Graser, Alexander Bruy
Book Image

QGIS 2 Cookbook

By: Alex Mandel, Víctor Olaya Ferrero, Anita Graser, Alexander Bruy

Overview of this book

QGIS is a user-friendly, cross-platform desktop geographic information system used to make maps and analyze spatial data. QGIS allows users to understand, question, interpret, and visualize spatial data in many ways that reveal relationships, patterns, and trends in the form of maps. This book is a collection of simple to advanced techniques that are needed in everyday geospatial work, and shows how to accomplish them with QGIS. You will begin by understanding the different types of data management techniques, as well as how data exploration works. You will then learn how to perform classic vector and raster analysis with QGIS, apart from creating time-based visualizations. Finally, you will learn how to create interactive and visually appealing maps with custom cartography. By the end of this book, you will have all the necessary knowledge to handle spatial data management, exploration, and visualization tasks in QGIS.
Table of Contents (19 chapters)
QGIS 2 Cookbook
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

Defining custom projections


Map projections stump just about everybody at some point in their GIS career, if not more often. If you're lucky, you just stick to the common ones that are known by everyone and your life is simple. Sometimes though, for a particular location or a custom map, you just need something a little different that isn't in the already vast QGIS projections database. (Often, these are also referred to as Coordinate Reference System (CRS) or Spatial Reference System (SRS).)

I'm not going to cover what the difference is between a Projection, Projected Coordinate System, and a Coordinate system. From a practical perspective in QGIS, you can pick the one that matches your data or your intended output. There's lots of little caveats that come with this, but a book or class is a much better place to get a handle on it.

Getting ready

For this recipe, we'll be using a custom graticule, a grid of lines every 10 degrees (10d_graticule.json.geojson), and the Natural Earth 1:10 million...