This table shows components of variation for particle size of Poudre valley gravel. Variance components are expressed as percent of total variance:

1-Between-site (downstream) variation is low for small particle size, but high for large particle sizes.

2-Between-section (local) variation is nil for most particle sizes.

3-Between-sample (error) variation dominates for small particle size but drops for large sizes.

4-The analysis indicates that coarse particle size parameters are suitable for mapping.

5-An analysis of variance of the sums of squares (not shown here) confirmed that sampling was adequate to distinguish measures of coarse particle size (PCT > 3/4 inch, PCT > 1.5 inch, median, Q3, estimated maximum size) at sites. Sometimes, sample plans must be adjusted to enable reliable distinction among objects of interest, such as sample sites along a valley reach.

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Last updated 07 Dec 2016