Читать книгу Global Approaches to Environmental Management on Military Training Ranges - Tracey Temple - Страница 41

The previous section discussed sampling theory and the primary sources of error described by that theory. There are two types of errors associated with all sampling: FSE, which is caused by compositional heterogeneity of the contaminant, and GSE, caused by the heterogeneous spatial distribution of the contaminant particles in the area to be characterized (DU) [7]. The DU cannot be sampled by simply going to the field, obtaining a few grams of soil, and analyzing the sample, unless there is no compositional or distributional error associated with the contaminant. FSE and GSE associated with a contaminant in a DU will render a discrete or grab sample meaningless. Inferences associated with any sample are based on distributional and compositional error and, for a grab sample, these inferences are quite limited. Rasemann goes into great detail on developing a range of values quantifying these errors for the sampling and analysis of industrial waste dumps [24]. His conclusion at the time of publication was that the greatest source of error in characterization is sampling error.