ECHELON APPROACH TO AREAS OF CONCERN IN SYNOPTIC REGIONAL MONITORING

Echelons provide an objective approach to prospecting for areas of pot ential concern in synoptic regional monitoring of a surface variable. Echelons can be regarded informally as stacked hillforms. The strategy is to identify regions of the surface which are elevated relative to surroundings (Relative ELEVATIONS or RELEVATIONS). These are areas whi ch would continue to expand as islands with receding (virtual) floodwa ters. Levels where islands would merge are critical elevations which d elimit echelons in the vertical dimension. Families of echelons consis t of surface sectors constituting separate islands for deeper waters t hat merge as water level declines. Pits which would hold water are dis regarded in such a progression, but a complementary analysis of pits i s obtained using the surface as a virtual mould to cast a counter-surf ace (bathymetric analysis). An echelon tree is a family tree of echelo ns with peaks as terminals and the lowest level as root. An echelon tr ee thus provides a dendrogram representation of surface topology which enables graph theoretic analysis and comparison of surface structures . Echelon topview maps show echelon cover sectors on the base plane. A n echelon table summarizes characteristics of echelons as instances or cases of hillform surface structure. Determination of echelons requir es only ordinal strength for the surface variable, and is thus appropr iate for environmental indices as well as measurements. Since echelons are inherent in a surface rather than perceptual they provide a basis for computer-intelligent understanding of surfaces. Echelons are give n for broad-scale mammalian species richness in Pennsylvania.