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

Using QGIS for publishing


QGIS offers a very easy and convenient way to publish QGIS projects with its own spatial server. It is the CGI application QGIS Server, which we have already configured in Chapter 1, Setting Up Your Environment.

Note

If you are using Windows, and could not configure QGIS Server properly, don't worry, just skip to the GeoServer part (Using GeoServer).

Similar to the popular UMN MapServer, QGIS Server is a simple CGI application which does not track the published data. While MapServer needs a configuration file where paths to the data sources are defined along with other configuration parameters, QGIS Server needs a QGIS project file, which contains the paths along with other information, like styling. We can provide the project file's absolute path in a map parameter.

Note

While web servers can only access a portion of the file system, CGI scripts can access anything they have permission to read or write. Always consider this when using CGI scripts.

Let's craft a URL which...