topic Re: Calculating Sinuosity Properly in ArcGIS Network Analyst Questions

Calculating Sinuosity Properly

EdwardGriffin — Thu, 25 Nov 2010 22:50:51 GMT

Hi

I am creating a network dataset and one of the impedences to travel time I want to use is sinuosity or the bendyness of a road segment.

It's pretty important that this is included as roads in New Zealand go over mountainous terrain and road bendyness is a real impendence to travel time.

It is easy to calculate sinuosity by using Hawthes tools. However, sinuosity is determined by how many line segments make up a line. If only one segment makes up a line the sinuosity will always be one. This in effect means that sinuosity for some roads is understated as actually there are 5 line segments - they are just not linked together to make up a line.

What I want to create a dataset where all segments between two junctions are linked to form one line

Does anybody have any ideas how to do this, i'm struggling to think of anyway this will be possible?

Cheers

Ed

Re: Calculating Sinuosity Properly

AlexeyTereshenkov — Fri, 26 Nov 2010 10:36:02 GMT

Hi Edward

I am a bit puzzled. Could you please clarify what exactly do you want to achieve?

As far as I got you, Dissolve Network tool might help (do you use ArcGIS 10?). But again, I might got you wrong.

Re: Calculating Sinuosity Properly

EdwardGriffin — Mon, 29 Nov 2010 18:47:38 GMT

Hi Alex

What I want is to only have one road segment between each junction on my road dataset. At the moment sometimes I have up to five road segments between two junctions and this causes errors when I want to measure sinuosity because the segments are usually all straight (but make up a bendy road when put together)

Not sure if that makes any sense?

Cheers

ed

Re: Calculating Sinuosity Properly

AlexeyTereshenkov — Mon, 29 Nov 2010 19:24:16 GMT

Hi Edward

I see. I assume that each road segment, i.e., a feature, has a specified speed value and other attributes. How are you going to deal with this? Are you fine with the idea of merging two adjacent road segments and assigning an average speed value and somehow a summed up travel time range?

And just one more thing. When you say junctions, do you mean junctions that are being created automatically when building a network dataset?

I will take a closer look at the data tomorrow at office.

Re: Calculating Sinuosity Properly

EdwardGriffin — Tue, 30 Nov 2010 23:56:39 GMT

Hi Alex

Yes your right each segment does have specific attributes.

What i was going to do is calculate the overall sinuosity for each new segment between two junctions and then apply that back to the individual road segments

So the final dataset will still have all the orginal segments with their orginal attributes but the true sinuosity value also be included.

(if that makes sense).

In terms of junctions, yes the junctions that are created in NA but only the ones that have >2 roads converging at them - as i think the junction s just mimic the road segments.

Cheers

Ed

Re: Calculating Sinuosity Properly

JaySandhu — Wed, 01 Dec 2010 13:52:34 GMT

Ed,

As Alex pointed out before, the GP Dissolve Network tool is what you want to use to remove the psuedo junctions (i.e. junctions with valency of 2). Then you can compute your sinuoisty property and apply it back to the original set of edges. Read more here:
http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#/Dissolve_Network/00480000000w000000/

Jay Sandhu

Re: Calculating Sinuosity Properly

EdwardGriffin — Wed, 02 Mar 2011 18:44:57 GMT

Hi Jay and Alex

I have only just noticed your replys. Thanks for your help on this - the dissolve function looks to be exactly what i'm after.

Cheers

Ed

Re: Calculating Sinuosity Properly

AlexeyTereshenkov — Wed, 02 Mar 2011 18:59:38 GMT

Hi Edward,

Glad it played out well for you. If you already have got ArcGIS 10, you might take a look at those new GP tools in Network Analyst toolbox Jay and other people from Network Analyst team provide us with. I use them on a regular basis and they are great!

Re: Calculating Sinuosity Properly

EdwardGriffin — Mon, 21 Mar 2011 00:49:51 GMT

Hi All

I have been trying to dissolve my road network but the I keep getting the same error on it: 030083 : Failed to dissolve the network dataset.

I have tried to trace this error and it is hard to understand what the problem is. I don't think there is anything wrong with the edges or the connectivity, and it doesn't have any elevation fields. It comes up short when it is trying to 'dissolve the feature chains'.

Any advice on this would be very gratefully received

cheers

Ed

Re: Calculating Sinuosity Properly

AlexeyTereshenkov — Mon, 21 Mar 2011 10:23:35 GMT

Hi,

Please check this document, hope this will solve your issue.
http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#//00vs00000005030083.htm

The help section for this GP tool is available at
http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#//00480000000w000000.htm

Keep us updated about the results.

Re: Calculating Sinuosity Properly

PaulBeere — Tue, 05 Aug 2014 07:01:55 GMT

Yo' Ed

I solved your problem. Let me guess, you didn't assign a Z Coordinate System for the Feature Dataset that contained your road network layer? Was having the same problem with the Dissolve Network tool falling over at 'Dissolving feature chains', and I also got the corresponding '030083' error. Tried changing the Dissolve Network tool's environmental variables so that 'M Values' and 'Z Values' were set to 'Disabled', but that didn't work. I then tried adding a proxy Z Value column to my roads layer with all features assigned a value of 0, and setting this as the Z attribute. That just threw up an entirely new error message.

Finally, I tried assigning a Z Coordinate System for the Feature Dataset that contained my road network layer and now it is working. I did not change any of the environmental variables. Turns out the GP tool was looking further up the chain for the Z geometry.

You are welcome

Paul

Re: Calculating Sinuosity Properly

NoxoloKheswa — Wed, 09 Nov 2022 10:31:23 GMT

Hi Paul,

I've tried this but now I get two warnings instead of one 🙃 any help will be highly appreciated.