topic Re: In Cost Path option to add Horizontal Factors - How do I convert table to raster? in ArcGIS Spatial Analyst Questions

In Cost Path option to add Horizontal Factors - How do I convert table to raster?

JeffChartrand — Thu, 22 Aug 2019 12:17:33 GMT

I want to add wind direction and strength to a cost distance surface. The Help file show example of file with two columns - Direction in Degrees, and second value strength (which I assume would cover the full 360 degree azimuth).

 0    1.40     10   2.43     20   2.30     30   3.44     40   1.25     50   1.02     60   0.90     70   0.86     80   0.25     90   0.78     100  1.49     110  2.35     120  3.32     130  2.39     140  3.18     150  2.13     160  1.89     170  1.20     180  2.034

How do I create a raster surface which incorporates these two factors to create a friction surface?

Do you have to create a direction surface, Wind Strength surface and add them together?

Is there a simple process to add all the friction costs together in one step?

Thanks in advance for any and all suggestions.

Jeff

Re: In Cost Path option to add Horizontal Factors - How do I convert table to raster?

SarmisthaChatterjee — Mon, 26 Aug 2019 20:13:26 GMT

Hi Jeff,

Please take a look at the blog here: Creating accumulative cost surfaces using directional data by James and Kevin in response to your question.

regards,

Sarmistha

Re: In Cost Path option to add Horizontal Factors - How do I convert table to raster?

JeffChartrand — Wed, 28 Aug 2019 13:18:39 GMT

Hi read the blog but still seem to be struggling with the process. I am trying to use wind direction and speed as an friction cost, sometimes in direction of movement, sometimes from side direction, and also in opposition to direction of movement. The blog does not make clear how you generate a raster incorperating the direction and strength of wind. Given a raster layer I assume it could be incorporated into the standard friction surface calculation or as a Horizontal factor. Do you have to produce two raster surfaces, one for direction, and one for wind strength?

Re: In Cost Path option to add Horizontal Factors - How do I convert table to raster?

Anonymous User — Wed, 28 Aug 2019 14:35:31 GMT

Hi Jeff

The blog had two goals:

1. To point out that it currently isn't possible to use both direction and speed with the Esri distance tools.

2. If using just direction is acceptable, then it points out some things you need to be aware of.

Enhancing the distance tools to deal with true vector fields is something we'll be investigating for future releases.

Regards,

Jim TenBrink

Re: In Cost Path option to add Horizontal Factors - How do I convert table to raster?

Anonymous User — Wed, 28 Aug 2019 15:04:43 GMT

> with the Esri distance tools.

that was a little vague: I should have said "... with the tools in the Distance toolset of the Spatial Analyst toolbox"

Re: In Cost Path option to add Horizontal Factors - How do I convert table to raster?

JeffChartrand — Thu, 29 Aug 2019 12:00:19 GMT

Thanks Jim. I had hopes that given the help file data on direction and horizontal and vertical factors that this might have been addressed. When sorted would make a good tutorial or practical.

Jeff