Whitebox GAT - an introduction by its developer

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The Whitebox Geospatial Analysis Tools Project

and Open-Access GIS

John Lindsay, Ph.D.University of Guelph

GISRUK, Glasgow April 16-18, 2014

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What is Whitebox GAT?

3http://www.uoguelph.ca/~hydrogeo/Whitebox/

• Origins in the Terrain Analysis System (TAS)• Whitebox GAT project started in 2009• Free and open-source GIS and remote sensing

software package• Google code repository• Multi-platform software• Translated into 11 languages

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Whitebox

• Currently contains 372 tools for processing DEMs, raster images, vector data, and LiDAR.

• New tools can be added as plugins developed using any JVM programming language (Java, Groovy, Python).

• Useful as a powerful geoprocessing engine

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Basic GIS and Vector Data Analysis

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Terrain Analysis Toolbox

• Tools for extracting information from DEMs.

• Surface derivatives (slope, aspect, curvature)

• Hillshading and visibility analysis• Relative landscape position• Landform classification• Topographic index, sediment

transport index, etc.

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LiDAR represents the state of the science for topographic and canopy mapping.

LiDAR Toolbox

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LiDAR Toolbox

• Whitebox contains tools to – interpolate LAS files, – mosaic tiles, – fill in missing data gaps, – remove off-terrain objects– model vegetation canopy

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Removing Off-terrain Objects

Original last-return LiDAR DEM Bare-Earth DEM created using ‘remove off-terrain objects’ tool

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Processing Massive DEM Datasets

This file was mosaiced from 4200 LiDAR tiles

It consists of 4.25 billion grid cells and a file of 15.8GB

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Hydrology Toolbox

Flow accumulation image derived from a DEM

• Flow-path enforcement• Flow algorithms • D8, FD8, D∞, MD∞• flow direction• flow accumulation

• Flow-path length• Watershed delineation • Sub-basin delineation• Hillslope mapping

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Surface Flow-path EnforcementDepression Filling

Depression Breaching

Road blocks flow in DEM

X

X

Filling Breaching

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Stream Network Analysis Toolbox

• DEM-based automated stream mapping– Algorithms based on either valley

recognition methods (i.e. DEM shape) or channel initiation methods (i.e. contributing area thresholding)

• Link length and slope• Stream ordering • Long profiles• Link classification

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Remote Sensing Applications

• Numerous spatial filters• Contrast stretching• Change detection algorithms• PCA and inverse PCA• Image classification, feature-space plotting• Photogrammetry

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Whitebox as an ‘Open-Access GIS’

• The potential benefits of O-S GIS include wider community involvement, deeper user knowledge, and rapid innovation in the field.

• The intention of O-S GIS is good but we could realize even more benefits if we altered the implementation.

• The potential benefit of OSS is often defeated by the barriers that are in place as a result of the implementation of the O-S model.

• Open-Access GIS: software should be designed in a way that reduces the barriers that often discourage or disallow end-users from examining the algorithm design and implementation associated with specific geospatial tools.

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Whitebox Usage

• Downloaded 1573 times in last 17 weeks.• Downloads originated in 91 countries

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Concluding remarks

• Whitebox provides extensive tools for extracting information from spatial data sets.

• The open-source(access) nature and ease of use of Whitebox provides an ideal environment for education and research.

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Acknowledgements

• It’s been a wonderful honour to speak with you today.

• Funding for this work has been provided by:

Whitebox GAT - an introduction by its developer

Technology

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