Judging survey quality: Local variances

The present study was undertaken to explore possibilities to judge survey q uality on basis of a limited and restricted number of a-priori observations . Here, quality is defined as the ratio between survey and local variance ( signal-to-noise ratio). The results indicate that the presented surveys do not permit such judgement. Furthermore, the discussion also suggests that t he 5-fold local sampling strategies do not merit any sound judgement in abo ut 10% of all cases. The results further imply that surveys will benefit fr om procedures, controls and approaches in sampling and sample handling, to assess both average, variance and the nature of the distribution of element al concentrations in local sites. This reasoning is compatible with the ide a of the site as a basic homogeneous survey unit, which is implicitly and c onceptually underlying any survey performed.