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

Calculating a hillshade layer

A hillshade layer is commonly used to enhance the appearance of a map and display topography in an intuitive way, by simulating a light source and the shadows it casts. This can be computed from a DEM by using this recipe.

Getting ready

Open the DEM that we prepared in the Preparing elevation data recipe.

How to do it…

  1. In the Processing Toolbox option, find the Hillshade algorithm and double-click on it to open it:

  2. Select the DEM in the Input layer field. Leave the rest of the parameters with their default values.

  3. Click on Run to run the algorithm.

The hillshade layer will be added to the QGIS project, as follows:

How it works…

As in the case of the slope, the algorithm is part of the GDAL library. You will see that the parameters are very similar to the slope case. This is because slope is used to compute the hillshade layer. Based on the slope and the aspect of the terrain in each cell and using the position of the sun that is defined by the Azimuth and Altitude fields...