Book Image

QGIS 2 Cookbook

By : Mandel, Olaya Ferrero, Anita Graser
Book Image

QGIS 2 Cookbook

By: Mandel, Olaya Ferrero, Anita Graser

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 (14 chapters)
13
Index

Dasymetric mapping


Dasymetric mapping is a technique that is commonly used to improve population distribution maps. By default, population is displayed using census data, which is usually available for geographic units, such as census tracts whose boundaries don't necessarily reflect the actual distribution of the population. To be able to model population distribution better, Dasymetric mapping enables us to map population density relative to land use. For example, population counts that are organized by census tracts can be more accurately distributed by removing unpopulated areas, such as water bodies or vacant land, from the census tract areas.

In this recipe, we will use data about populated urban areas, as well as data about water bodies to refine our census tract population data.

Getting ready

To follow this exercise, please load the population data from census_wake2000_pop.shp (the file that we created in Chapter 2, Data Management), as well as the urban areas from urbanarea.shp, and...