reshape buffesr to avoid and reflect excluded areas?

Discussion created by johns on May 23, 2012
Latest reply on May 24, 2012 by johns
We need to create buffers around various polygons, but non-forested polygons cannot be a part of the buffers.  This is not a simple erase problem; the buffer needs to be "expanded" to avoid any NF polygons within it, treating them in a sense as if they were space that didn't exist, to get the required buffer distance in forested areas.  Normally this buffer reshaping is easily understood but manually intensive, a one by one process with a considerable subjective component and some trial and error, as additions are made to the outer edge of the buffer approximating the excluded shape, such that imagined lines running perpendicular from the outer edge of the buffered polygon would roughly go through the same length of feet of forested polygons as the buffer distance.

These NF polygons may abut the buffered polygons but more likely they don't, they may occupy just a portion of the buffer, their shapes are often quite irregular, and they often extend outside the initial buffer to create areas that can't be expanded into either.  At least we don't have to factor in 3D.  The buffers do need to have attributes that link them to the buffered polygons.  We have ArcInfo and Spatial Analyst.

An automated and repeatable "objective" process that worked pretty well would be preferable.  After looking at a discussion of how Maplex places labels by looking for "white space" outside features with a higher weight or labels of a higher priority, I wondered if a buffering process could be created that would avoid excluded areas.  To my quite limited abilities this seems darn near impossible, but I've seen some answers on this Forum and Stack Exchange that have solved other issues I couldn't grasp either, so I'll ask.