Book Image

QGIS Blueprints

By : Ben Mearns
Book Image

QGIS Blueprints

By: Ben Mearns

Overview of this book

Table of Contents (14 chapters)
QGIS Blueprints
About the Author
About the Reviewers


QGIS, the world's most popular free/open source desktop geographic information system software, enables a wide variety of use cases involving location—formerly only available through expensive, specialized commercial software. However, designing and executing a multitiered project from scratch on this complex ecosystem remains a significant challenge.

This book starts with a primer on QGIS and closely-related data, software, and systems. We'll guide you through seven use-case blueprints for geographic web applications. Each blueprint boils down a complex workflow into steps that you can follow to reduce the time usually lost to trial and error.

By the end of this book, readers will be able to build complex layered applications that visualize multiple datasets, employ different types of visualization, and give end users the ability to interact with and manipulate this data for the purpose of analysis.

What this book covers

Chapter 1, Exploring Places—from Concept to Interface, gives you an overview of the application types and technical aspects that will be covered and how QGIS will be leveraged. through a simple map application example from the digital humanities. You will use some fundamental GIS techniques to produce a tile cache-leveraging web application that includes geocoded addresses, joined data, and a georeferenced image.

Chapter 2, Identifying the Best Places, will look at how raster data can be analyzed, enhanced, and used for map production. You will produce suitability grids using map algebra and export to produce a simple click-based map.

Chapter 3, Discovering Physical Relationships, will create an application for physical raster modeling. We will use raster analysis and a model automation tool to model the physical conditions for some basic hydrological analysis. Finally, you will use a cloud platform to enable dynamic query from the client-side application code.

Chapter 4, Finding the Best Way to Get There, will explore formal, network-like geographic relationships between vector objects. You will learn to create a few visualizations related to optimal paths: isochron polygons and accumulated traffic lines. The end result will be an application that will communicate back and forth with your audience regarding safe school routes.

Chapter 5, Demonstrating Change, will demonstrate visualization and analytical techniques to explore relationships between place and time and between places themselves. You will work with demographic data from a census for election purposes through a timeline controlled animation.

Chapter 6, Estimating Unknown Values, will use interpolation methods to estimate unknown values at one location based on the known values at other locations using the NetCDF array-oriented scientific data format. You will use parameters such as precipitation, relative humidity, and temperature to predict the vulnerability of fields and crops to mildew.

Chapter 7, Mapping for Enterprises and Communities, will use a mix of web services to provide a collaborative data system. You will create an editable and data-rich map for the discovery of community information by accessing information about community assets.

What you need for this book

You will need:

  • QGIS 2.10

  • A computer running OS X, Windows, or Linux

Who this book is for

This book is for relatively experienced GIS developers who have a strong grounding in the fundamentals of GIS development. They must have used QGIS before, but are looking to understand how to develop more complex, layered map applications that effectively expose various datasets and visualizations.


In this book, you will find a number of text styles that distinguish between different kinds of information. Here are some examples of these styles and an explanation of their meaning.

Code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles are shown as follows: "Run QTiles, creating a new mytiles tileset with a minimum zoom of 14 and maximum of 16."

A block of code is set as follows:

[..] > cd c:\packt\c4\data\output
c:\packt\c4\data\output>java -jar osm2po-5.0.0\osm2po-core-5.0.0-signed.jar cmd=tj
sp newark_osm.osm

Any command-line input or output is written as follows:

cd C:\packt\c6\data\web
python -m CGIHTTPServer 8000

New terms and important words are shown in bold. Words that you see on the screen, for example, in menus or dialog boxes, appear in the text like this: "Navigate to Layer | Open attribute table."


Warnings or important notes appear in a box like this.


Tips and tricks appear like this.

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