QGIS blueprints : develop analytical location-based web applications with QGIS / Ben Mearns.

Format:

Book

Author/Creator:

Mearns, Ben, author.

Series:

Community experience distilled.

Community experience distilled

Language:

English

Subjects (All):

Cartography--Computer programs.

Cartography.

Geographic information systems--Computer programs.

Geographic information systems.

Computer software.

Electronic data processing.

Geospatial data.

Physical Description:

1 online resource (258 p.)

Place of Publication:

Birmingham : Packt Publishing, 2015.

Summary:

Develop analytical location-based web applications with QGIS About This Book Tame geographic information workflows with QGIS blueprints for smart web applications Create geographic web applications using QGIS and free/open source software Blueprints provide real-world applications covering many use cases Who This Book Is For This book encompasses relatively experienced GIS developers who have a strong grounding in the fundamentals of GIS development. They will have used QGIS before, but are looking to understand how to develop more complex, layered map applications that expose various data sets, utilize different visualizations, and are consumable (usable) by end users What You Will Learn Review geographic information principles and the application of these principles in the QGIS free/open source ecosystem Perform advanced analysis with site selection, hydrologic, and topological networks Build performant web applications by tile caching and generating static assets Provide collaborative editing capabilities for your team or community Develop custom and dynamic analysis and visualization capabilities Select the best components from desktop and web, for your use case Integrate it with social media and crowdsourcing In Detail QGIS, the world's most popular free/open source desktop geographic information system software, enables a wide variety of use cases involving location - previously only available through expensive specialized commercial software. However, designing and executing a multi-tiered 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 six use-case blueprints for geographic web applications. Each blueprint boils down a complex workflow into steps you can follow to reduce time lost to trial and error. By the end of this book readers should be able to build complex layered applications that visualize multiple data sets, employing different types of visualization, and give end users the ability to interact with and manipulate this data for the purpose of analysis. Style and approach This is a comprehensive guide to the application of QGIS and free/open source software in creating web applications from analysis. Step-by-step blueprints guide the reader through analytical and web development topics and designs."

Contents:

Cover; Copyright; Credits; About the Author; About the Reviewers; www.PacktPub.com; Table of Contents; Preface; Chapter 1: Exploring Places - from Concept to Interface; The software; The development community and dependencies; Data format read/write; Geospatial coordinate transformation; Analysis; Web publishing; Installation; Linux; Mac; Windows; OSGeo-Live; Acquiring data for geospatial applications; Producing geospatial data with georeferencing; Table join; Geocode; Orthorectify; The spatial reference manipulation - making the coordinates line up; Setting CRS; Transformation and projection

Visualizing GIS dataThe layer style; Labels; The basemap; Using OpenStreetMap for the basemap data; Avoiding obscurity and confusion; The layer scale dependency; The label conflict; Tile caches; Generating and testing a simple directory-based tile cache structure; Create a layer description file for the TileLayer plugin; Summary; Chapter 2: Identifying the Best Places; Vector data - Extract, Transform, and Load; Loading data and establishing the CRS conformity; The extracting (filtering) features; Converting to raster; Doing more at once-working in batch; Raster analysis; Map algebra

Additive modelingProximity; Slope; Combining the criteria with Map Calculator; Zonal statistics; Publishing the results as a web application; qgis2leaf; Summary; Chapter 3: Discovering Physical Relationships; Hydrological modeling; Preparing the data; Filling the grid sinks; Clipping the grid to study the area by mask layer; Modeling the hydrological network based on elevation; Workflow automation with the graphical models; Spatial join for a performant operational layer interaction; The CartoDB platform; Publishing the data to CartoDB; Preparing a CartoDB SQL Query; Generating the test data

The CartoDB SQL view tabThe QGIS CartoDB plugin; The CartoDB SQL API; Leaflet and an external API: CartoDB SQL; Summary; Chapter 4: Finding the Best Way to Get There; Postgres with PostGIS and pgRouting; Installing Postgres/PostGIS/pgRouting; Creating a new Postgres database; Registering the PostGIS and pgRouting extensions; OpenStreetMap data for topology; Downloading the OSM data; Adding the data to the map; Projecting the OSM data; Splitting all the lines at intersections; Database importing and topological relationships; Connecting to the database; Importing into PostGIS with DB Manager

Creating the topological network dataAn alternate workflow: topology with osm2po; Using the pgRouting Layer plugin to test; Creating the travel time isochron polygons; Generating the travel time for each road segment; Creating isochron polygons; Converting the travel time lines to points; Selecting the travel time ranges in points and creating convex hulls; Generating the shortest paths for all students; Finding the associated segment for a student location; Calculating the accumulated shortest paths by segment; Flow symbology; Web applications - creating safe corridors

Registering a Twitter account and API access

Notes:

Description based upon print version of record.

Description based on online resource; title from PDF title page (ebrary, viewed January 12, 2016).

ISBN:

9781785284090

1785284096