2.3. Statistical analyses and mapping
Statistical analyses were performed with SPSS for
Windows 10.0.5. Data were log-transformed prior
principal component analysis to reduce the influence
of high values. Principal component analysis was
conducted using factor extraction with an eigenvalue
>1 after varimax rotation. Concentrations were pair
wise compared using a one-way analysis of variance
(ANOVA). If the main effects were significant at
P < 0.05, a post-hoc separation of means was done
by univariate least significance difference (LSD) test.
The basis for the attached maps was the topographic
map of 1979 from the north eastern Ghouta, with a
scale 1:25000 (Department of Survey of Syria, 1979a;
Department of Survey of Syria, 1979b) and the Landsat
TM scene 174–037 from 30 July 1994.