Showing posts with label mountain. Show all posts
Showing posts with label mountain. Show all posts

Sunday, 21 March 2021

Munro maps and stats

I've been working on this on and off for ages, so I think it's time to publish what I've got and then move on. See below for a collection of maps and stats relating to Scottish Munros. You what? Just in case anyone reading this isn't aware, a 'Munro' is a mountain in Scotland with a height of 3,000ft or more, or 914.4 metres in modern parlance. The reason we're not using metric measurements here is that Sir Hugh Munro published his first list of peaks in 1891. Anyway, let's start with a simple map of all 282 Munros and then I'll look at how many are within 100 miles of Scotland's cities, and within a 90 minute drive + 5km. I also generated a distance matrix so you can see how far each Munro is from all the others - based on this measure, Beinn Teallach is the most central Munro (it's only just barely a Munro as well, by about 25cm).

All 282 Munros
Nine of them are above 4,000ft

In the maps above, I have used Ordnance Survey Terrain 50 data to create the terrain effect, and I made the maps in QGIS. I did a bit of post-QGIS processing to add a bit of 'noise' and also to recolour the maps, but the mapping was done in QGIS, like I said. I used the Scotland digital terrain model I created and have shared on my new business website, over at Automatic Knowledge. For the location of Munros, I used The Database of British and Irish Hills v17.1, which is really great.

The next thing I did was decide to look at how many Munros were within 100 miles of major cities - for this I chose Aberdeen, Dundee, Edinburgh, Fort William, Glasgow, Inverness, Perth and Stirling. I added in Fort William to the mix because even though it's not as big as the others, it is right in the heart of all the Munros so it would have been daft to leave it out. By my calculations, here's how many Munros there are within 100 miles of each of these places - and see below that for the maps of each one. The point in each places that I measured from was where the Ordnance Survey data I used put the place point - generally right in the city centre.

  • Aberdeen - 95 Munros within 100 miles
  • Dundee - 201
  • Edinburgh - 171
  • Fort William - 280
  • Glasgow - 203
  • Inverness - 282 (all of them)
  • Perth - 232
  • Stirling - 226








What about within 50 miles? 100 miles as-the-crow-flies gets you quite a long way, but given the terrain it can be a lot longer than that when you are actually trying to get there. So, I looked at it using a 50 mile buffer as well - see below for the data on that, plus the 50 mile maps for Fort William and Inverness.

  • Aberdeen - 10 Munros within 50 miles
  • Dundee - 55
  • Edinburgh - 3
  • Fort William - 193 (68% of them)
  • Glasgow - 38
  • Inverness - 141
  • Perth - 92
  • Stirling - 56


Okay, if you want to move to the Highlands and become a professional Munro-bagger, it's pretty obvious that Inverness or Fort William is where you need to be, but we already knew that. What I didn't know was exactly how many peaks were near each place. But of course this straight line kind of analysis is only really useful if you're a) a bird or b) have your own helicopter that can somehow fly directly to the top of mountains in - not easy when they are very often covered in clouds! Talking of clouds, I've used a cloud-style buffer mask on purpose here.

I have only been to the top of a very small number of Munros (not sure how many but definitely at least two, just can't remember), am generally quite scared of exposed drops, and am not into competitive mountainy things, but I do quite like making maps of this stuff because it reminds me of where I'm from. 

But let's say you want to do some kind of analysis that will help you understand - in a more practical way - how many Munros are near each city. That's what I decided to do. Based on an early morning departure time (06:00) at a weekend, driving 90 minutes at reasonable speeds, and then taking a 5km buffer around the 90 minute travel isochrone (calculated using the TravelTime plugin in QGIS), I came up with a number that I think looks about right for each of my eight places. See below for the results and the maps. Obviously, if you drive like a maniac and there's no traffic, you'll get different results, but these numbers seem about right, based on some additional manual checking. I've made the edge of the travel time zones a bit fuzzy, just to avoid the impression that there is a 100% precise cut-off. Plus I wanted it to look cloudy too, as I said above.

  • Aberdeen - 0 Munros within 90 minute drive + 5km
  • Dundee - 13
  • Edinburgh - 1
  • Fort William - 127 (45% of them)
  • Glasgow - 37
  • Inverness - 81
  • Perth - 54
  • Stirling - 51








Okay, so we're finally getting somewhere. Actually, we aren't. We're all stuck at home, apart from some people fortunate enough to be near these lovely places. By the way, those links I just put in are to the twitter accounts of Iain Cameron and Kelly Lander - two of my absolute favourite accounts - you may already know them if you're reading this but if not I highly recommend following them. Talking of incredible things - I'm still astounded by Donnie Campbell's Munro-round record of 31 days - he climbed all 282 in only 31 days last year - read about it here. Yes, that is an average of 9 Munros per DAY. Mind you, Hazel Strachan's Munro accomplishments over many years are also just exhausting to think about!

So, you want to know how far each Munro peak is from the top of Ben Nevis? Of course you do. First, here's a map of what that might look like. Read the text on the image for more info.


I generated a distance matrix - and a GeoPackage of it, for GIS users - so you can see how far each Munro is from all the others, in metres, kilometres and miles. 

I published this in list format and matrix format in the folder for this little side project. You'll also find higher resolution images of each of the maps above - the ones here are only half the size of the originals, although they are still pretty big.

There's loads more I could do on this, but I need to move on now. 

Hopefully some people will find this interesting. I'll leave you with a selection of photos I took last September on a trip up Ben Lawers and Beinn Ghlas, on a surprisingly lovely day. The second one was my attempt to zoom in to Ben Nevis, which we could see that day - it's 34.5 miles away from Ben Lawers.











Notes: yes, 3,000ft or 914 metres doesn't sound like much if you're from a much bumpier country. But if you are more than 3,000ft up a mountain at 57 degrees north, with a biting, gale force wind trying to knock you off your feet, 3,000ft can seem like 30,000! I could have calculated the distance between Munro peaks using a digital elevation model surface rather than straight line distance but that would a) be more complicated and time consuming and b) not be that useful if I only used the 50 metre open dataset I have available. I've compared this kind of thing before using straight line vs topographical distance and the results didn't change that much, but if anyone has done it please let me know. 

Wednesday, 28 December 2016

Interactive Terrain Mapping in QGIS

During last year's winter break I did a little animation of Arctic sea ice, which eventually ended up being shown in slightly modified format in Svalbard Museum - and they even sent me a nice hat for my efforts. This year's spare time project was to look a bit more at terrain mapping in QGIS, with a purpose. Since I'm a Highlander in exile I dream of the hills quite a lot, and the mountains in particular. If you follow mountain weather reports for the Highlands, you'll hear of fairly regular avalanches. They may not have the ferocity of avalanches elsewhere in the world, but they can be deadly. The Scottish Avalanche Information Service do a great job of recording, documenting, mapping and educating here so I thought I'd add this data to some 3D interactives using Minoru Akagi's Qgis2threejs QGIS plugin and Ordnance Survey Open Data. If that sounds like gobbledygook to you, never mind - just look at the little animation below to see one of the outputs. The red dots are the locations of recorded avalanches since 1991. You can also play around with it in your web browser - it's quite good fun.


Avalanche data is from the Scottish Avalanche Information Service

I extracted the avalanche data from the SAIS webmap and just plotted the locations in QGIS. I decided to focus on an area I know relatively well - the Cairngorm mountain area. It's not high by world standards, at 1,245m/4,085 feet (6th highest in the UK), but at 57 degrees north and nothing much protecting it from the fierce winter weather, conditions up there can be extreme. In fact, I remember growing up sitting many times on the old chairlift as it swung in the wind! Not for the faint hearted. Anyway, as is the way with these things, the area I wanted to look at was split between map tiles, as you can see below in this QGIS screenshot.

I think there must be a name for the law of split map tiles

Methods-wise, I just patched together a few map tiles, clipped out the area I wanted to focus on, overlaid the avalanche location data, generated a hillshade with an azimuth of 180 and elevation of 27 (to simulate shadows at noon on 26 December), and then added some Ordnance Survey map tile data on top of it. I also did a version with Google satellite imagery, just to see what kind of result I could get. I've posted a little gif of the satellite version below, followed by more of the images. You can also play around with a smaller version of this in your web browser. It should also work on phones, but you might have to use three fingers to pan around.

This uses Google satellite imagery - interactive here

What you'll see below in the next five images are just screenshots from the final interactive from my web browser. You should see them in larger size if you click on them. I've modified some of the settings slightly but basically it's quite an easy thing to do in QGIS with the Qgis2threejs plugin. The updated document on this (18 Oct 2016) is also available in a single, handy pdf. If you want to use this tool, you'll find lots of useful tips in here.


Full view of the final interactive - looking north

Focused on Loch Avon (pronounced Loch A'an

This shows the main areas of avalanche activity in one view 

This is a view with the Lairig Ghru pass in the foreground

Another more vertical view of the southern part of the area

I like the effect here with the hillshade layer providing some sense of depth and shadow. There is no vertical exaggeration here and in the interactive version you can zoom in quite far before it becomes pixellated. I also wanted to see what kind of quality I could get by adding in a Google satellite layer and then exporting that. For this, I used the OpenLayers plugin in QGIS (though QuickMapServices is also really good for this). The final version was pretty big as I exported at a high resolution, but here are some snapshots.

The full view of the satellite version - click to enlarge

Loch Etchachan - watch this video!

A different view, showing a cluster of recorded avalanches

The resolution here is actually quite good

This is a view from 'over the back' of the ski area

One final overview image, just for completeness

As I said above, I also did a little extract of this focusing on a smaller area around Loch Avon. The satellite imagery changes part way along the loch but it's still quite pleasing. The interactive version works pretty well in the browser and the image quality here is also pretty good (I exported this at 200% in the Qgis2threejs settings).


Loch Avon - a nice little video from March 2016

It's not always winter here - take a look

Along the way, I almost forgot why I started to map this - the purpose was to plot some interesting and important data on top of the terrain in order to try to understand more about which areas are particularly prone to avalanches. Along the way, I learned more about Mike Spencer's snow hydrology research and PhD (more on that here) and found out some stuff that will help me update my teaching material on this topic. I did begin to look at the Ben Nevis area as well (below), but I decided to focus on the Cairngorms instead this time.

25 years of avalanche locations (red dots) for the Nevis Range

That's all for now. Thanks to the kind of data collected by the SAIS, Ordnance Survey Open Data, and great tools like QGIS and Qgis2threejs, it's becoming much easier to explore, analyse, visualise and understand important datasets. That is kind of what I was attempting here, as a little holiday experiment.

Thanks for reading.


Map data: Contains OS data © Crown copyright and database right 2016