I am building a suitability regression for a tree plantation. Like many things related to flora, elevation, slope, and aspect are important variables for growth and thus site selection. However, I am trying to wrap my head around how each of these can be used if 2 (slope and aspect) are derived from the 3rd (DEM). Is this analytically acceptable? Is there a way to account for the correlation and the error which must propagate?
Any advice, opinion and insight is welcome.