spatialEco (version 2.0-1)

hli.pt: Point estimate of Heat Load Index

Description

Calculates the McCune & Keon (2002) Heat Load Index

Usage

hli.pt(
  alpha,
  theta,
  latitude,
  direct = FALSE,
  scaled = TRUE,
  force.hemisphere = c("none", "southern", "northern")
)

Value

Vector of McCune & Keon (2002) Heat Load Index

Arguments

alpha

Aspect in degrees

theta

Slope in degrees

latitude

A latitude representing the centrality of the data

direct

Boolean (FALSE/TRUE) Return direct incident radiation else HLI (default)

scaled

Boolean (TRUE/FALSE) Apply arithmetic scale using EXP(h)

force.hemisphere

If country is split at the equator, force southern or northern hemisphere equation c("southern", "northern")

Author

Jeffrey S. Evans <[e-mail]>

References

McCune, B., and D. Keon (2002) Equations for potential annual direct incident radiation and heat load index. Journal of Vegetation Science. 13:603-606.

McCune, B. (2007). Improved estimates of incident radiation and heat load using non-parametric regression against topographic variables. Journal of Vegetation Science 18:751-754.

Examples

# Single input
hli.pt(theta=180, alpha=30, latitude=40) 

# Multiple input, returns results from 
#   McCune, B., and D. Keon (2002)
# Raw -0.2551 -0.6280 0.0538 -0.6760 -1.1401 -0.2215
# arithmetic scale 0.7748 0.5337 1.0553 0.5086 0.3198 0.8013

slp = c(0, 30, 30, 0, 30, 30)
asp =c(0, 0, 180, 0, 0, 180)
lat =c(40, 40, 40, 60, 60, 60)
hli.pt(theta = slp, alpha = asp, latitude = lat)