Simpson's 1/3 Rule -
 I = (b-a)[(f(xo) + 4Xf(xi) +2Ef(x2)+f(xn))/3n] [1]
 I = area under the cross section curve
 a = length at x = 0, tip of hummock
 b = length at x = n, end of hummock
 f(xo,1,2,n) = value on y-axis, height of hummock
 xl = the odd number points
 x2 = even number points up to but excluding xn
 n = number of points

 Simpson's 3/8 Rule
 I = (b-a)[(f(xo) + 3f(xi) +3f(x2)+f(x3))/8] [2]
 I = area under the curve
 a = length value at x = 0, tip of hummock
 b = length value at x = n, end of hummock
 f(x0,1,2,3) = value on y-axis, height of hummock

 The change in area during each measurement period was used to calculate the
percent change in hummock elevation. Percent change in area was determined by
subtracting the new area from the original area and dividing the result by the original
area.


Change in Area

 % Change = (Ao -A1)/Ao [3]
 Ao = original area
 Ai = new area

 Cross sectional areas calculated for each hummock were compared to the original
value to find changes over time. The changes indicate the amount of degradation in the
hummock surface.


WATER LEVEL MEASUREMENT

 Water level was recorded to relate the soil moisture in each hummock with the
height of the water relative to each hummock. Stevens Type F water-level recorders
Model 68 were installed in the Agrifos and the Cargill wetlands. Data were not collected
during the first growing season however, because the recorders were not installed until
mid-October. Water levels were determined by taking height readings at multiple points
along the edge of the standing water. Elevations of the water surface were then
determined using the same process as for hummock elevations.


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