Resolution of the spatial variability in sediment composition within and between water-storage reservoirs using non-parametric statistical techniques

Non-parametric statistical techniques, specifically Multi-Dimensional Scaling (MDS), Analysis of Similarity (ANOSIM) and Similarity Percentages (SIMPER) are used to resolve the spatial variability of sediment composition based on major element distribution within and between two reservoirs in adjacent catchments which were to be used as the experimental and control sites in a de-stratification experiment. MDS analysis indicates that sediments separate into four groups, three from one dam and one from the second dam. ANOSIM analysis showed that there was a statistically significant difference between these four groups. SIMPER analysis shows that there is a high degree of similarity for sites within each of the four groups. In all cases, greater than 60% of the similarity within each group was explained by three elements—Si, Al and Fe. However, the elements responsible for the dissimilarity between groups of sites were more variable.