SMZ compliance is also periodically checked by a state forester and reported to establish the credibility of the system. These inspections require numerous site visits and on the ground measurements. Both the precision of operational plans and the time necessary to validate compliance could be improved by a GIS procedure that would correctly plot SMZ's on overlays for remote images or aerial photographs. This paper presents four different GIS approaches to modeling SMZ's as defined by South Carolina's BMP's and attempts to evaluate the relative tradeoffs of precision and time between them. Outlines for automating these approaches in a GIS macro language are presented along with the relative amount of time necessary for each approach to map the same stream network.
Precision is discussed relative to guideline definitions and relative areas mapped.
A most practical approach is selected from those presented and recommend for South Carolina's BMP guidelines, however, different approaches will satisfy different objectives.