Background:

A common function in standard GIS software enables users to create a raster surface and extract values or clip it based on a set of polygons. This may be used in cases where you want analysis to be constrained to within a town’s boundaries or a coastline. This tutorial will outline how to create a surface using kernel density estimation (KDE) and then clip the surface so that it is constrained within the City of London Boundary.

Data Requirements:

City of London Boundary Shapefile: Download (requires unzipping).

London Cycle Hire Locations: Download.

Install the following packages (if you haven’t done so already):

sm, maptools.

Click here to view the code.

Background:
In some cases it is necessary to conduct the same analysis multiple times on either the same or different data. In such circumstances it is worth writing a function to simplify the code. In this example the location quotient provides a simple calculation easily written in to a function.

The location quotient (LQ) is an index for comparing a region’s share of a particular activity with the share of that same activity found at a more aggregate spatial level (a good book on this kind of thing is Burt et al.). In this example we take a shapefile of London Boroughs that contains information on the population of each borough and the percentage of sports participation in each borough. In this case there is little point in calculating the LQ as the percentage alone would be more meaningful. The focus here is how to undertake the methods, not their appropriate use, or the validity of the results.

Data Requirements:

London Sport Participation Shapefile: Download (requires unzipping)

Install the following packages (if you haven’t already done so):

maptools, RColorBrewer.

Click here to view the tutorial code.

This is an updated version of my Making Maps with R tutorial. I think the code is lot simpler and it also includes some data for you to play around with.

Background:

Spatial data are becoming increasingly common, as are the tools available in R to process it. Of course one of the best ways of visualizing spatial data is through a map. Maps need to be well thought out. Not least, the selected colours need to be appropriate and sufficient context is provided through the use of a legend, title, scale bar and north arrow. The worksheet will demonstrate how to produce a map with R that includes all these elements.

Data Requirements:

London Sport Participation Shapefile. Download (requires unzipping)

Install the following packages (if you haven’t already done so):

maptools, RColorBrewer, classInt

Click here to view the tutorial code.

As I have mentioned before I have really enjoyed my trips to Iceland and Inspired by Iceland is a great project to promote the wonders of the country. It has a great website with excellent quality webcams that enable full screen viewing of three of Iceland’s landmarks: Reykjavik, Gullfoss and Jökulsárlón. My favourite is Jökulsárlón, often known as Iceland’s glacier lagoon. Just for fun I set about creating a time-lapse using screen shots from the webcam. The video below is the outcome of this (best viewed full-screen or on Vimeo). I took a screen shot of the webcam image every minute for 24hours (starting at 1900 hours). The images were then processed to convert them from colour to black and white and I also added some blurring around the top and bottom of each frame to create a tilt-shift effect. William Cheshire kindly provided the music.

Sound maps are nothing new but they are becoming increasingly popular as technology (such as Google Maps and Audioboo) are making their creation much easier. My interest in these stems from the Sounds Like Leigh-On-Sea project my brother is creating of our hometown (map below).

View Sounds Like Leigh-on-Sea in a larger map
There are several other larger-scale projects that have caught my eye recently. The London Sound Survey is one of the most mature projects with sounds from most of London, and recent plans to expand east along the Thames Estuary.

On a National Scale the Noise Futures Network and British Library have teamed up to create the UK Soundmap with the intention of creating a crowd-sourced soundscape of the UK. It has only recently been launched so there is space for many more contributions!

One of my favorite maps is from sonicwonders.org with its “travel guide to sonic wonders‘. Sounds can be rated as ‘worth a journey’, ‘worth a detour’ and ‘interesting’ and it can certainly add another dimension to holiday plans.

Worthy of a final mention is the BBC’s Audio Map of the World because it is the most extensive I have seen (it even has recordings from Antarctica!).

I think sound maps are yet to come of age. It would be nice to see the large scale creation of georeferenced sound recordings uploaded online in a similar way that photos are on Flickr. I think they could make for a really interesting data source and could produce some great maps and applications.

When I was digging around some back-up files on my computer I came across this “How to…” published by the Guardian Newspaper in 2007. With many new geography students starting their respective courses in the coming weeks and many potential students considering applications to the subject in the coming months this may prove a useful guide. It’s a pretty good summary of the discipline (although I don’t know many human geographers interested in trams and of course there is no mention of GIS).  Click here, or image, for full size.

In case you were wondering, to my knowledge, geographers still haven’t worked out why the sea fits so snugly around the coastline…

Before I dust down my corduroy jacket in preparation for the geography conference season, the article reminds me of the “what is geography?” question I prepared an answer for when applying for my undergrad. degree. If only I had thought of an answer as concise as Starbucks…

Photo from Isla Johns

As part of my PhD research I recently produced the map below (high res. version) that shows the diversity of surnames in Great Britain. I wanted to demonstrate that surname diversity is not uniform across Great Britain. For example towns and cities (especially London) have relatively high surname diversities compared with rural areas because more migrants and single people live in them. Wales has a very low surname diversity due to its past naming conventions. The measure used is calculated by dividing the number of surnames by the total population of each Output Area (OA). There are over 200,000 OAs in Britain. Urban OAs are very small despite accounting for a large proportion of the total population, so I have scaled the size of each OA by their population (the map is therefore a cartogram). This creates the somewhat bloated appearance of Great Britain, but serves to emphasise the increased surname diversity (due to more single people and migrants) in towns and cities. The correct shape of Great Britain is shown in the inset. For more technical info please see below.

To create this map I used ArcGIS 10 and the Cartogram Geoprocessing Tool. The nice thing about the tool is that it is not dependent on VBA and therefore worked straight off in ArcGIS 10. There are over 220,000 spatial units in this map and the tool had no problems processing them. I have not found any alternatives that work for this volume of data.

Last week I heard that the London School of Economics Geography Department was disposing of its maps and that anyone interested was free to rescue them. My first reaction was one of surprise as maps are one of the few things geographers are associated with, so it doesn’t seem right to have a geography department without a map room. My more rational side, however, understands that a change of research priorities within geography, combined with the fact that all up to date maps are now stored digitally probably means that the map room drawers have remained shut for a number of years. As universities expand there is an increasing demand for space and the “use it or lose it” policy is likely to apply.

So it fell to a number of enthusiasts to save the maps. I think the majority have been rescued and will be given new life as posters, artworks or simply keepsakes to be pulled out and admired on a rainy day. Rifling through the maps was a bit like going through an old photo album. Snapshots from the past, such as maps showing the narrow air corridor in 1970s Germany

or the size of the Haut Glacier d’Arolla glacier and famously retreating Unterer Grindelwladgletscher 75 years ago cast insights into a world before my time.

For something closer to home, I picked up some really nice maps from the “Phillips Series of Comparative Wall Atlases” (dated 1956) that show the summer and winter temperatures across the British Isles. I suspect that today we can add a couple of degrees to many of the contour lines drawn on the maps.

My favorite find is a couple of Ordnance Survey maps of the Greenwich Area dated 1917, though some lucky person had made off with the rest of London! Highlights from the maps include the “Thames Soap and Candle Works”

and detailed outlines of the housing.

If anyone knows what the colours mean I would be interested in hearing from them…

I think it is a real shame that such a great collection of maps has had to be broken up and I suspect LSE Geography will not be the last to send its maps to recycling. Still every cloud has a sliver lining and I am now trying to find the wall space to hang my newly acquired maps!

Thanks to Ollie O’Brien for the tip off about the map room giveaway.

My review of Rogerson and Yamada’s Statistical Detection and Surveillance of Geographic Clusters has just been published in the journal Environment and Planning B. Overall I thought the book was very useful and have consulted it many times in my own work. You can read the full review here.