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Mastering QGIS

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Mastering QGIS

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Mastering QGIS
Mar, 2015 | 420 pages
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Table of Contents (18 chapters)
Mastering QGIS
Mastering QGIS
Credits
Credits
Foreword
Foreword
About the Authors
About the Authors
About the Reviewers
About the Reviewers
www.PacktPub.com
www.PacktPub.com
Preface
Preface
Free Chapter
1
A Refreshing Look at QGIS
A Refreshing Look at QGIS
QGIS download and installation
Tour of QGIS
Loading data
Working with coordinate reference systems
Working with tables
Editing data
Composing maps
Adding functionality with plugins
Summary
2
Creating Spatial Databases
Creating Spatial Databases
Fundamental database concepts
Creating a spatial database
Importing data into a SpatiaLite database
Exporting tables out of SpatiaLite as a shapefile
Managing tables
Creating queries and views
Summary
3
Styling Raster and Vector Data
Styling Raster and Vector Data
Choosing and managing colors
Managing color ramps
Styling single band rasters
Styling multiband rasters
Creating a raster composite
Raster color rendering
Raster resampling
Styling vectors
Vector layer rendering
Using diagrams to display thematic data
Saving, loading, and setting default styles
Summary
4
Preparing Vector Data for Processing
Preparing Vector Data for Processing
Merging shapefiles
Creating spatial indices
Checking for geometry errors
Converting vector geometries
Using basic vector geoprocessing tools
Defining coordinate reference systems
Advanced field calculations
Complex spatial and aspatial queries
Summary
5
Preparing Raster Data for Processing
Preparing Raster Data for Processing
Reclassifying rasters
Rescaling rasters
Creating a raster mosaic
Generating raster overviews (pyramids)
Converting between raster and vector data models
Creating raster surfaces via interpolation
Summary
6
Advanced Data Creation and Editing
Advanced Data Creation and Editing
Creating points from coordinate data
Geocoding address-based data
Georeferencing imagery
Checking the topology of vector data
Repairing topological errors via topological editing
Summary
7
The Processing Toolbox
The Processing Toolbox
About the processing toolbox
Performing raster analyses with GRASS
SAGA
Exploring hydrologic analyses with TauDEM
R
Summary
8
Automating Workflows with the Graphical Modeler
Automating Workflows with the Graphical Modeler
An introduction to the graphical modeler
Opening the graphical modeler
Configuring the modeler and naming a model
Adding inputs
Adding algorithms
Running a model
Editing a model
Documenting a model
Saving, loading, and exporting models
Executing model algorithms iteratively
Nesting models
Using batch processing with models
Converting a model into a Python script
Summary
9
Creating QGIS Plugins with PyQGIS and Problem Solving
Creating QGIS Plugins with PyQGIS and Problem Solving
Webography - where to get API information and PyQGIS help
The Python Console
Exploring iface and QGis
Exploring a QGIS API in the Python Console
Creating a plugin structure with Plugin Builder
A simple plugin example
Setting up a debugging environment
Debugging session example
Summary
10
PyQGIS Scripting
PyQGIS Scripting
Where to learn Python basics
Loading layers
Vector structure
Iterating over features
Editing features
Running processing toolbox algorithms
Running an external algorithm or command
Interacting with the map canvas
Summary
Index
Index

Exploring hydrologic analyses with TauDEM

The TauDEM (short form for Terrain Analysis Using Digital Elevation Models) environment contains a suite of tools with a specific emphasis on hydrologic and surface flow analysis. GRASS and SAGA also contain some algorithms that calculate similar parameters, but TauDEM has a comprehensive suite of tools in a single location.

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

  • Elevation file (dems_10m.dem, available in the GRASS data folder)

  • Gauge shapefile (gauge.shp)

  • Rivers file (hydl.shp)

To explore the functionality of TauDEM, we will characterize the watershed of Sun Creek upstream to the town of Fort Klamath, California. To accomplish this, we will perform the following tasks:

  1. Remove pits from the DEM.

  2. Calculate flow directions across the landscape.

  3. Calculate the upstream area above Fort Klamath.

  4. Calculate a stream network raster grid.

  5. Create a watershed-specific vector stream network.

    Tip

    Reminder about...

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