912
HUFF
Table 1— RELATIVE VARIABILITY OF GROSS BETA RADIOACTIVITY
AND STORM RAINFALL ON KASKASKIA AND BONEYARD NETWORKS
_
Date,
1962
Relative variability, %
Network
Storm
rainfall
Beta
concentration
Beta
deposition
Mean
rainfall
depth, in.
May
May
May
May
May
10
10
26
26
27
Boneyard
Kaskaskia
Boneyard
Kaskaskia
Boneyard
7
4
9
24
8
22
13
38
25
10
20
14
30
20
16
0.68
0.72
0.51
0.46
0.53
May
June
June
June
July
27
8
9~10
9—10
2
Kaskaskia
Boneyard
Boneyard
Kaskaskia
Boneyard
20
23
6
6
12
44
15
20
11
29
58
27
20
14
24
0.43
0.53
1.08
1.18
1.00
Kaskaskia
Boneyard
Kaskaskia
Kaskaskia
Boneyard
44
6
17
13
18
23
24
10
39
52
20
26
10
28
o4
0,41
3.84
3.59
1.95
0.27
14
25
25
July 2
July 2-3
July 2-3
July 14-15
August 24
Average
rainfall in the 15-storm sample of Table 1. In 12 of the 15 storms, the
beta variability exceeded the storm-rainfall variability.
A slight trend was found for the gross beta variability to decrease
with increasing mean rainfall and storm duration. The same slight
trends
were
found with storm-rainfall variability. Studies by the
Illinois State Water Survey® and the U. S. Weather Bureau’ have shown
that the relative variability of storm rainfall varies inversely with
mean rainfall and storm duration. This is in agreement with the trends
observed in the 15-storm sample. Thus it appears that the relative
variability of both the rainwater radioactivity and the storm rainfall
tends to decrease with increasing storm duration and mean rainfall,
which is not surprising since rainfall is the carrier of the radioactivity.
Correlation coefficients were calculated between the variables of
Table 1 to evaluate further the trends previously discussed. The cor-
relation coefficients were calculated from the logarithms of the numbers since graphical plots of the data indicated exponential relations.
These coefficients, which indicate relatively low correlations, are
presented in Table 2. Although they are weak, the correlations support
the slight trends discussed earlier.
The relative variability discussed in the preceding paragraphs
provides a measure of the average dispersion about the mean. Table 3
provides a measure of the maximum variation of gross beta and storm
rainfall within the Boneyard and the Kaskaskia networks. This table