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
About the Authors
About the Reviewers

Georeferencing vector layers

For various reasons, sometimes you have a vector layer that lacks projection information. This is often the case with CAD layers that were created only in local coordinates. When it is possible, try to track down the original projection information. As a last resort, you can attempt to warp the vector layer to match a known reference layer with the recipe described here.

Getting ready

You can open two instances of QGIS (or use one as you'll just be zooming back and forth a lot). In one instance, load a reference layer, something in the projection that you want your data to be in. Activate Coordinate Capture Plugin from the Manage Plugins menu.


In Windows, you need the osgeo4w shell for this recipe. If you don't have a start menu item, look for the OSGeo4W.bat launcher in your QGIS or OSGeo4w installation folder.

This example uses cad-lines-only.shp, which is the line layer extracted from the CSS-SITE-CIV.dxf file. This file is a CAD rendering of design plans...