Book Image

Hands-On Geospatial Analysis with R and QGIS

By : Shammunul Islam, Brad Hamson
Book Image

Hands-On Geospatial Analysis with R and QGIS

By: Shammunul Islam, Brad Hamson

Overview of this book

Managing spatial data has always been challenging and it's getting more complex as the size of data increases. Spatial data is actually big data and you need different tools and techniques to work your way around to model and create different workflows. R and QGIS have powerful features that can make this job easier. This book is your companion for applying machine learning algorithms on GIS and remote sensing data. You’ll start by gaining an understanding of the nature of spatial data and installing R and QGIS. Then, you’ll learn how to use different R packages to import, export, and visualize data, before doing the same in QGIS. Screenshots are included to ease your understanding. Moving on, you’ll learn about different aspects of managing and analyzing spatial data, before diving into advanced topics. You’ll create powerful data visualizations using ggplot2, ggmap, raster, and other packages of R. You’ll learn how to use QGIS 3.2.2 to visualize and manage (create, edit, and format) spatial data. Different types of spatial analysis are also covered using R. Finally, you’ll work with landslide data from Bangladesh to create a landslide susceptibility map using different machine learning algorithms. By reading this book, you’ll transition from being a beginner to an intermediate user of GIS and remote sensing data in no time.
Table of Contents (12 chapters)
8
GRASS, Graphical Modelers, and Web Mapping

Spatial interpolation

Spatial interpolation is a technique for predicting spatial data in a place where there is no observed data. This technique uses observed data for interpolation. Now we'll work with arbitrary meteorological data recorded in several locations of areas surrounding Dhaka, Bangladesh. We'll predict temperature at every point of the raster that covers this area. For doing so, we consider the raster of the Digital Elevation Model (DEM) and use its extent to generate a raster and plot point data on this raster. Then, using different interpolation techniques, we'll predict temperatures at every other point of the raster file.

Nearest-neighbor interpolation

We'll then convert this raster data...