I'r - Memorial University of Newfoundland

5.1 SPATIAL DI STRIBUTION
s. DISCUSSION
The panems ofspatw distribution emerging from the independentanalyses of
molecular and isotopic data euibit strong resemblance. The kngthwise profiles showed
that the lake can be split into three distinct zones with regard to both molecular and
isotopic signatures. In addition. both principal components analyses showed that a
certain crosswise pertem separating northern and southern stations exists in the central
part ofthe lake. A generalized two dimensional pattern was statistically generated by
clus tering three principal components extracted from both mo lecular and isotopic data
sets. A detailed description oCthe approach to the clustering procedure can be found in
lite chapter dealing with methods (Section 32.2). Prior to the analysis. the components
were weighted with respect [0 the percentage ofvariance explained in each PeA
(Appendix CI). The output of cluster .maIysis. which employed the oon-bicrarchtc.al (K.
means) technique. is presented in Appendix C I and reproduced in Table 5.1.1. Sites
associated with the identified clusters Conn three prominent zones which were named
acco rding to their relative position and proximity to the major industrial centers: the City
Zone, the South Zone. and the North Zone (Fig. 5.1.1). Within eacb ofthese zones, the
molecular and isotopic composition orPAH are broadly similar and can beinterpreted. in
terms of transport and redistribution by primary and secondarycirculation of lake
contamination (introduced largely through fluvial input at major cities) superimposed on
ISl