Statistical Analysis of Trends in the Red River Over a 45 Year Period

Table 5.1: Comparison Results with respective p-values
Station # Constituent Non-Parametric Parametric
1. dissolved calcium < 0.001 n/a
1. dissolved sodium < 0.001 < 0.001
1. dissolved potassium < 0.001 < 0.001
1. dissolved magnesium < 0.001 < 0.001
1. dissolved sulphate < 0.001 n/a
3. dissolved sulphate < 0.001 n/a
1. dissolved chloride 0.330 0.001
3. dissolved chloride < 0.001 n/a
1. total dissolved solids < 0.001 < 0.001
2. total dissolved solids 0.005 n/a
3. total dissolved solids 0.003 n/a
1. specific conductance < 0.001 0.001
2. specific conductance 0.337 < 0.001
3. specific conductance 0.424 < 0.001
Figure 4.7 there seems to be no visible trend. Another commonality between the
methods, is that there was only enough data from the Emerson station to be used
for those constituents. Total dissolved solids was significant at the Emerson station
using both methods, however the data from the South Floodway and Selkirk
stations were too sparse to employ the parametric method. There are also some
obvious differences. For example, using non-parametric techniques dissolved chloride
concentrations at the Emerson monitoring station did not exhibit a significant
trend. Preliminary results suggest that this also is true for specific conductance at
the South Floodway and Selkirk monitoring stations. Using parametric techniques
specific conductance at both stations had significant increases which proves to be
an interesting contradiction. Table 5.1 summarizes the comparisons of each method
with their respective p-values.
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