Heat Load Index - is this value in the formula wrong?

[paolabarajas]

Dear Jeffrey Evans,

I have a question about a value in the HLI formula you wrote in the PDF, where you describe the Geomorphometry & Gradient Metrics toolbox for ArcGIS (https://github.com/jeffreyevans/GradientMetrics/blob/master/READ%20ME.pdf).

In your PDF the formula for HLI appears like this:
HLI = 0.039 + [0.808 ∗ cos(𝑙) ∗ cos (𝜃)] − [0.196 ∗ sin(𝜃)] − [0.482 ∗ cos(𝑓(𝛼)) ∗ sin(𝑓(𝛼))]

Then you cite McCune & Keon, 2002, as they are the authors of the formula. But, I see that in Table 2 of McCune & Keon, 2002 the value is different, i.e., 0.339.

I would assume this may be a typo in your PDF document, right?

This I just spot last week thanks to a very friendly and detailed review I got from a paper I submitted. I am using some of your metrics in my research.

Best, Paola

[jeffreyevans]

I will check on this but, off the top of my head, there are two McCune papers the second being a modification to the original formula. Best, Jeff Jeffrey S. Evans, Ph.D., | Senior Landscape Ecologist & Biometrician The Nature Conservancy | Protected Lands Science Visiting Professor | University of Wyoming | Zoology & Physology Laramie, WY | [email protected]<mailto:[email protected]> | (970) 672-6766<tel:(970)%20672-6766> From: Paola Barajas Barbosa <[email protected]> Sent: Thursday, April 23, 2020 12:46 PM To: jeffreyevans/GradientMetrics <[email protected]> Cc: Subscribed <[email protected]> Subject: [jeffreyevans/GradientMetrics] Heat Load Index - is this value in the formula wrong? (#7) Dear Jeffrey Evans, I have a question about a value in the HLI formula you wrote in the PDF, where you describe the Geomorphometry & Gradient Metrics toolbox for ArcGIS (https://github.com/jeffreyevans/GradientMetrics/blob/master/READ%20ME.pdf<https://github.com/jeffreyevans/GradientMetrics/blob/master/READ%20ME.pdf>). In your PDF the formula for HLI appears like this: HLI = 0.039 + [0.808 ∗ cos(𝑙) ∗ cos (𝜃)] − [0.196 ∗ sin(𝜃)] − [0.482 ∗ cos(𝑓(𝛼)) ∗ sin(𝑓(𝛼))] Then you cite McCune & Keon, 2002, as they are the authors of the formula. But, I see that in Table 2 of McCune & Keon, 2002 the value is different, i.e., 0.339. I would assume this may be a typo in your PDF document, right? This I just spot last week thanks to a very friendly and detailed review I got from a paper I submitted. I am using some of your metrics in my research. Looking forward to your response about this little issue. Best, Paola — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub<#7>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/ACLKH74WRCGTRNTHPODOGNTROCEFLANCNFSM4MPKUUTQ>.

[paolabarajas]

Thank you very much for your prompt answer. Just in case, the McCune & Keon paper where I found the equation is https://doi.org/10.1111/j.1654-1103.2002.tb02087.x

Also, thanks a lot for the effort you put in making all this nice the tools available for us.

Paola Barajas
[email protected]
[email protected]

[jeffreyevans]

It is the McCune (2007) “Improved estimates of incident radiation and heat load using non-parametric regression against topographic variables<https://onlinelibrary.wiley.com/doi/10.1111/j.1654-1103.2007.tb02590.x>” paper that provides the corrections used in the toolbox. Please, also be aware that I am no longer developing this toolbox as ESRI is just making it to difficult to maintain code around their software. I have provided all of these functions, excluding CTI, in the R package spatialEco, available on CRAN and GitHub. Best, Jeff From: Paola Barajas Barbosa <[email protected]> Sent: Thursday, April 23, 2020 1:53 PM To: jeffreyevans/GradientMetrics <[email protected]> Cc: Jeffrey Evans <[email protected]>; Comment <[email protected]> Subject: Re: [jeffreyevans/GradientMetrics] Heat Load Index - is this value in the formula wrong? (#7) Thank you very much for your prompt answer. Just in case, the McCune & Keon paper where I found the equation is https://doi.org/10.1111/j.1654-1103.2002.tb02087.x<https://doi.org/10.1111/j.1654-1103.2002.tb02087.x> Also thanks a lot for the effort you put in making all this nice the tools available for us :) — You are receiving this because you commented. Reply to this email directly, view it on GitHub<#7 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/ACLKH7YB32JLFHNOLX6Z3XTROCMA3ANCNFSM4MPKUUTQ>.