to the extent possible, provide compatibility and • The classification system should be capable of func- 



consistency with existing classification systems tioning in readily accessible, computer-operated 



(Hirsch and others 1978). information systems (Frayer and others 1978). 



The classification system should be hierarchical so • The classification system should be based on ecolog- 



that through aggregation and disaggregation it can ical principles and measurable or readily inferable 



provide decisionmaking information at several ad- features of the land, so that units of the classifica- 



ministrative or geographic levels (Nelson and others tion are identifiable by on-the-ground examination. 

 1978). 



