. Annual program report, 1989. Acidic Precipitation in Ontario Study; Acid precipitation (Meteorology); Acid pollution of rivers, lakes, etc; Acid rain. - 16 - LIMITS OF ACCURACY SOX CONnOCNCC. 2 J 4 s e n 1011 I2UI4I5I 18 19 2021 22 2324 252627 282930 Jl 32 3JJ4 A pMEW Figure 19. Number of sights needed to be grouped together to obtain level of accuracy (80?o confidence). between horizons and emphasize the need for sampling to occur by horizon rather than by depth. Improvement in reducing sample variability could be achieved by pooling samples obtained from a much larger area than can b
. Annual program report, 1989. Acidic Precipitation in Ontario Study; Acid precipitation (Meteorology); Acid pollution of rivers, lakes, etc; Acid rain. - 16 - LIMITS OF ACCURACY SOX CONnOCNCC. 2 J 4 s e n 1011 I2UI4I5I 18 19 2021 22 2324 252627 282930 Jl 32 3JJ4 A pMEW Figure 19. Number of sights needed to be grouped together to obtain level of accuracy (80?o confidence). between horizons and emphasize the need for sampling to occur by horizon rather than by depth. Improvement in reducing sample variability could be achieved by pooling samples obtained from a much larger area than can be obtained from a soil pit ( by using a soil corer). Nine of the measured properties showed statistically significant changes in mean values by year. Many of these properties, such as clay content, silt content and organic carbon, would not be expected to show any noticeable change in a short time. The apparent increase in silt content from 1982 to 1983 may be due to an increase in dithionite extractable iron and aluminum and the binding of clay sized particles into silt sized particles. However, no natural physical process could explain the large increase in organic matter content in one year, hence, the yearly changes observed in these properties may be a result of the intensive sampling procedure itself, in conjunction with normal soil forming processes, creating altered conditions in the second year. A dilemma is thus created; if one is to sample intensively enough to properly characterize the spatial variability, there is a possibility that the sampling could affect subsequent measurements and bias estimates of temporal variability. Five parameters showed significant decreases in from 1982 to 1983. All were metals, and all but one (zinc) exist in more than one valence state. Since 1982 was a very cold and wet year (coldest since 1929), reducing environments would have existed for much longer in 1982 than in 1983. Reduced forms of metals are more mobile than their
Size: 1919px × 1302px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorontarioministryoftheenvironment, booksubjectacidpollu
