Jul 282015

I know thesriuc_2015_smallat Esri story maps have been around for quite a while, but I am only finally learning how to create them now. For some reason, I was quite resistant to using them, but now that I have created a couple I have to say they could be really useful for teaching both GIS and just about anything geographical (I know my friends at Esri would be rolling their eyes – what can I say, I’m a slow learner!). The user interface for creating them could still use some tweaks, as I found there was a lot of clicking involved, but I have not yet tried uploading using a CSV file, which I have a feeling would alleviate that problem.

The first story map I created uses photos I took on a little walking tour from my hotel to Stanley Park and back in Vancouver, when I was there for the Canadian Association of Geographers Conference in June. I have a GPS receiver for my Canon 70D and I have to say it works like a charm! The receiver gets a signal within a couple of minutes, and then my photos are automatically geotagged. Of course, I also used my MotionX GPS app to record my track, which I have included in the story map as a separate map layer. It was a cloudy day, so the photos aren’t exactly spectacular, but it’s not too bad as a first effort. Maybe I’m just too new to this, but the embedded version below doesn’t seem as intuitive as the “full” version when it’s opened in a new window. (Edit: I tweaked the widths of my website page elements, so now the embedded versions render in their correct, “full” versions – much better. I also changed the Vancouver base map to satellite imagery).

I hope to experiment with the different templates available in the future but, for now, the basic walking tour format seemed to work best. I have also created one with photos from the Esri Education GIS Conference and main User Conference (click here to open in a new window):

Note: one thing I have noticed is that, if my browser window is too large, or too tall and skinny, the story map doesn’t render properly. I read on GeoNet that apparently it interprets the dimensions as being on a mobile device – Esri is working on fixing this. If this happens, you can just reduce the height of your browser window until it renders it correctly (it seems to want to be wider than high).

This first foray into Esri’s online applications is part of my new commitment to making better use of the Esri platform, beyond the traditional desktop suite. While I was at the User Conference, I had an “aha!” moment where I realized that all of the various components that Esri has been talking about for the past two or three years have matured and coalesced into a coherent and powerful platform. I’m sure that was their plan all along, but I have a feeling I’m not the only user who’s taken a while to figure out what it all means.


Oct 142011

I was skimming through my Twitter stream this morning and came across a tweet from the intrepid Michael Gould (@michael_d_gould) mentioning David J. Unwin’s digital workbook “Numbers aren’t nasty: a workbook of spatial concepts“.  I’m a big fan of David Unwin’s Geographic Information Analysis (co-authored with David O’Sullivan), so I downloaded the workbook (it’s free) and the accompanying data sets.  I was intrigued to see that this included coordinate data for John Snow‘s map of cholera deaths.  Virtually every GIS student learns about the pioneering epidemiological work John Snow did using spatial analysis of cholera deaths, tracing them to the infamous Broad Street pump.  I thought I would be clever and quickly map them using Google Fusion Tables.  What I soon realized was that the coordinates were created using an arbitrary system that placed them somewhere in Africa and, as is often the case, realized that I needed to slow down, take a closer look at the data and what I was doing, and see what was going on.

First, I did some quick online searching, and was surprised that I wasn’t able to find a georeferenced version of the data.  So I went back to the data at hand.  In Unwin’s workbook, he states that the points were originally “digitized at the request of Professor Waldo Tobler (UCSB) by Rusty Dodson of the US National Center for Geographic Information Analysis from a reprint of Snow’s book On Cholera (Oxford University Press, London)”. Since the original data had an arbitrary coordinate system, I used ArcGIS 10 to georeference an image of the map using the Bing Maps hybrid base map, and then spatially adjusted the points (both deaths and pump locations) to match the image.  I then used the ArcGIS Online topographic base map to create the following figure:

Locations of water pumps and cholera deaths

Locations of water pumps and cholera deaths from John Snow's map (the Broad Street pump is the blue symbol at the center of the map)


As this is based on a sketch map scanned from a book, all locations should be treated as approximate.

I must admit that I have sometimes neglected to mention John Snow and his work in my introductory GIS course (for shame!), so now I have some actual GIS data and a modern map to show in class.  It may also turn into a good opportunity to introduce web mapping as well.  After I saw Michael Gould’s original tweet, he and I discussed how we had both been meaning to find the replica Broad Street pump in London (tip: the street is now called Broadwick).  Naturally, Mike tweeted a link to an ArcGIS Explorer map of pump locations which of course inspired me to put my version of the pump and death locations on there as well:

View Larger Map

I hadn’t used ArcGIS Explorer much, and intend to incorporate it into my courses, so this was a good excuse to try it out.  Once I got it on the web, I did another search and found that someone else had already put a similar version online – oh well!  At least I learned a lot by going through this exercise, and what else was I going to do on a Friday afternoon?

I should also mention that I came across a simple but very interesting example of spatial analysis of the data done by what appears to be a student named John Mack.  His web page inspired me to start fooling around with the kernel density tool, and I came up with a quick example:

Density of cholera deaths from John Snow's map

Density of cholera deaths using a 100 m kernel density function

I will be the first to say I made this as a quick example, and would not put too much faith in it.  However, I may spend more time on this later, as it might be a good data set for illustrating density analysis.

So, there you have it.  Out of one tweet I read this morning came an entire day’s activity and some data and figures I can use in one of my GIS courses.  Twitter can eat up a lot of time, but sometimes I come across little gems that can be really interesting and useful.

Update: I have created a map data layer package of the pump and death locations that can be downloaded from ArcGIS.com.

Update: I have created zipped shapefile and KML versions of the files as well, both in GCS (WGS84).  In both versions, there are three files: one file contains one point location of the Broad Street Pump, one files includes all of the pumps in the original map (including the Broad Street pump) and one file contains the cholera deaths recorded on the map.


Aug 162011

Simultaneously published at V1 Magazine with thanks to Matt Ball, co-founder and editor, Vector1 Media.

Not that long ago, I considered “web mapping” an advanced topic, best left to be taught in a senior GIS course.  While that can still be the case, depending on how it is defined, the fact is that creating a map of your own data on a web page has become something anyone can do in a matter of minutes.  This was recently made clear to me when I decided to find out what Google Fusion Tables were, as I had been hearing a lot about them on Twitter and Google+ (particularly by the prolific and informative  Mano Marks, Senior Developer Advocate, Google Inc.).  I was amazed that I was able to geocode a list of one hundred postal codes using Google Fusion Tables less than five minutes after I learned what Fusion Tables even were.  I was struck by how useful this would be for my introductory GIS course to quickly get students’ attention, establish the relevance of what they would be learning, and promote discussion of several topics that would be covered in the course, including data input, map design, coordinate systems, projections, and interpretation and analysis of geographic data.

In the past, I have asked students to anonymously provide their postal codes on the first day of class so that I could geocode them in ArcGIS and then use this as a launching point for a discussion on geocoding, the spatial resolution of postal data, and what might be interpreted from their locations.  Now I see using Google Fusion Tables as a way to take this a step further, by allowing students to try it themselves and see how easy it is to collect data and create their own web map.

Students are already familiar with web maps in general and, likely, with Google maps in particular.  They already understand and appreciate the power of web maps.  My hope is that the simple act of creating their own custom-made Google map with their own data will empower them.  In other words, they will realize that they can do this themselves, and embed the results in any web page.  They can now move from passively mapping addresses in the standard Google Maps interface to more proactively mapping their own data in their own way.

With this simple exercise, students can see geography in action; how data can be collected,  mapped, and then analyzed and interpreted.  They can start to think spatially and analytically: How many students live within 1 km of the classroom?  How many live more than 10 km away?  What can they say about the points – are they clustered? Random? A bit of both? Does distance affect the pattern (e.g., clustered close to campus, but more random with increasing distance)?

Students can also be encouraged to critique the results of this web mapping exercise: Is there a legend?  Is there much flexibility in choice of symbology?  What do they like or dislike about the Google base map?  How does scale affect the data displayed and the representation of it?  If we zoom in and out from the local to the regional, national, and international level, how does the look of the map change?  This is a great way to introduce map projections and their scale-dependence (i.e., that different projections are appropriate for different scales).  Since I will not have introduced the concept of geocoding beforehand, I can ask them how Google “knows” where to place the points for the postal codes.  This will get them thinking about data sources and the “behind the scenes” data processing that goes on in order to make a seemingly simple map.

My approach has always been that, since many of my students will only take one GIS course, the main emphasis of that course should be on learning to create a well-designed and useful map, as that is likely to be the most useful skill for them.  My traditional assumption, which I now realize is rather old-fashioned, is that the maps they would want to create would be printed or perhaps used in a PDF file created for a report.  The reality is that the more likely medium they will want to use is the web.  Even the most casual mappers will want to share something online and, by teaching them how to do this early in their first GIS course, I believe this will give them a sense of empowerment and motivation that will, in turn, help them become more engaged with the course material.  To be sure, more complex web mapping is still something that is more appropriate for an advanced class (and a different instructor) but introducing some of the fundamental capabilities early on can provide a great opportunity for getting new GIS students interested in mapping and geographical analysis.

P.S. I realized after I posted this that I hadn’t actually included my little test case, so here it is: