Book Image

Mastering Geospatial Development with QGIS 3.x - Third Edition

By : Shammunul Islam, Simon Miles, Kurt Menke, GISP, Richard Smith Jr., GISP, Luigi Pirelli, John Van Hoesen, GISP
Book Image

Mastering Geospatial Development with QGIS 3.x - Third Edition

By: Shammunul Islam, Simon Miles, Kurt Menke, GISP, Richard Smith Jr., GISP, Luigi Pirelli, John Van Hoesen, GISP

Overview of this book

QGIS is an open source solution to GIS and widely used by GIS professionals all over the world. It is the leading alternative to proprietary GIS software. Although QGIS is described as intuitive, it is also, by default, complex. Knowing which tools to use and how to apply them is essential to producing valuable deliverables on time. Starting with a refresher on the QGIS basics and getting you acquainted with the latest QGIS 3.6 updates, this book will take you all the way through to teaching you how to create a spatial database and a GeoPackage. Next, you will learn how to style raster and vector data by choosing and managing different colors. The book will then focus on processing raster and vector data. You will be then taught advanced applications, such as creating and editing vector data. Along with that, you will also learn about the newly updated Processing Toolbox, which will help you develop the advanced data visualizations. The book will then explain to you the graphic modeler, how to create QGIS plugins with PyQGIS, and how to integrate Python analysis scripts with QGIS. By the end of the book, you will understand how to work with all aspects of QGIS and will be ready to use it for any type of GIS work.
Table of Contents (18 chapters)
Title Page
Copyright and Credits
About Packt
Contributors
Preface
Index

Performing analysis using SAGA


The System for Automated Geoscientific Automation (SAGA) environment contains powerful tools, some of which have very specific applications; for example, geostatistical analyses or fire and erosion modeling. However, we will explore some of the SAGA tools that have broader applications and often dovetail nicely with tools from other providers. Similar to GRASS, integrating the SAGA algorithms within the Processing Toolbox provides access to powerful tools within a single interface.

To explore some of the SAGA algorithms available through the Toolbox, we will work through a hypothetical situation and perform the analysis to evaluate the potential roosting habitat for the northern spotted owl.

We are going to continue using data from the provided ZIP file, and we will need the following files:

  • The elevation file (dems_10m.dem, available in the GRASS data folder)
  • The hillshade file (hillshade.tif, created in the GRASS section)
  • The boundary file (crlabndyp.shp)
  • The surface...