QGIS Network analysis: speed for walking time, considering ascent

I'm fairly new to QGIS and I'm doing a personal historical project on some network analysis for my local area. I've got my points and my road/path network, distance matrix, etc. However I can't help but think the numbers on walking time is out. I've been using the QNEAT3 plugin adjusting the default speed settings.

Does anyone know of Naismith's walking rule is taken into account, allow one hour for every 3 miles (5 km) forward, plus an additional hour for every 2,000 feet (600 m) of ascent?

Or if there is a way to do specific network analysis for walking?

• @Babel, here is a personal historical project ^_^ Commented Dec 15, 2021 at 15:01
• @Taras : saw it, see my answer - however, there is not much historical in this answer, could be for current pedestrian speed as well ;-) Commented Dec 15, 2021 at 15:19
• @Taras not sure how many other people would be interesting in how long it takes to walk to the Parish Church. Basically in the 1600s Scotland everyone was required to attend church. The parish measures roughly 9 miles east to west and 10 miles north to south. Always wondered how long it would take some of the outlining settlements to get there.... Commented Dec 15, 2021 at 15:23

You can create an attribute in you network layer for the total cost, consisting of length of each network segment as well as the ascent. This is, of course, dependent on direction: what is upwards in one direction is downwards in the other direction. SO use different values/input fields for forward and backward direction.

So you must have an information about the ascent for each segment or calculate it (from a DEM). The values you provided are: 1 hour = 3600 s for 5000 m horizontal and 600 vertical distance, that means: 1 m horizontal takes 0.72 seconds (1.39 m/s or 5 km/h) and 1 m vertical distance takes 3.6 s (0.17 m/s or 0.612 km/h).

Thus you have this formula for the time that is necessary for each segment: `length * 0.72 + ascent * 3.6 = total cost in seconds`. To get the speed, divide the horizontal distance by this time.

In the field calculator, create a new field `speed` using this formula, where `ascent` is the field name with values you have for ascent:

``````\$length / (\$length * 0.72 + "ascent" * 3.6)
``````

Then use this field as input in QNEAT3 dialog window for the [optional] speed field.

• That's brilliant. I've got a DEM for the parish so I can use that for calculating the ascent. Thanks for your help. Commented Dec 15, 2021 at 15:27