A Map for All Seasons — A New Path for Hikers
By: Richard Vahrman
Tags: Python, Qgis, Maps, Hiking, GIS

Follow the path around the central cyan shapes

I have always been a bit of a walker and one of the first things I would do when going somewhere on holiday was to buy an Ordnance Survey map of the area and a book of walks. Sometimes the walk was good but often it was only ok. There was never a bad walk. The quality of the writing was sometime mediocre and often the illustrations and maps left something to be desired. And often I got lost — but I got better. And better, and better at choosing a good book from a bad one.

Skip many years and enter the digital age. I think I paid around £300 for my first GPS device and immediately started to create my own routes — something that I loved doing and still do to this day. Creating a pleasing walk is every bit as enjoyable as a fine wine: even more so when it is an area I know little of. Or walking the length of the country (Cape of Ness to Brighton) which I navigated entirely with my phone in 2012. And then, yes, my Garmin was relegated to my discarded gadget drawer, once smartphones came along. Here’s one of my latest routes, created using an app called Viewranger.

Enjoyable as this is, I have always wanted a program that would allow me to generate a route automatically — and, indeed, these do exist now (e.g. Plotaroute, Routeshuffle) but, ironically, what they do is a bit too automatic. Pick a starting point. Add the route distance. Press a button. Hey presto.

I want something different — to tinker — to mod — to include certain features — to keep away from rivers when it has been raining a lot — to walk in the woods when there are mushrooms or bluebells — to explore the whole of an area when on holiday. And now I think I have found the answer.

In the map above, I have coloured areas that are bordered by paths or quiet roads. Big roads are ignored. You can now happily walk around any one area, or you could join two or more adjacent sections and you would be able to walk around the whole perimeter (see the example at the top of the page).

This doesn’t exist yet — above is just a map with some fancy colours on top. In my imagined version one will be presented with the above and each of the areas can be clicked on or off. As you add them, the perimeter of the selection will be automatically calculated as the amount of height gain/loss. Areas can be colour-coded to indicate features such as woods, rivers, views and could even be rated by users for beauty, quality of surface etc.

Modern art?

An unexpected outcome of this method is that a whole new method of navigation can be seen. For example, starting from the arrow a clockwise path can be described as YG, YR, YB, BG etc. Or in other words, yellow on my left and green on my right until it changes to yellow on my left and red on my right. (Don’t follow red/green). It then becomes yellow/ blue etc. If you want to walk in an anticlockwise direction, YG becomes GY. I can envisage a simple app (or even on your smartwatch) that alerts you at every colour change and indicates the new direction (alerting you if is detects that the colours are wrong).

Implementation. I think I have worked out a way of making the app and it involves QGIS and Python. QGIS is a free open source geographic information system (GIS) application that supports viewing, editing, and analysis of geospatial data. This would be used to create a polygon layer (the shapes) that are bounded by footpaths (a lot of work required here). This information is held within a database which can be manipulated ins software. The Python programming language is integrated with QGIS and the next stage is to learn how to use it — watch this space!