Geoscience Reference
In-Depth Information
d
d
d
d
−
−
−
−
k
k
k
k
te
Pmed
=
a
*
e
+
b
*
ze
+
c
*
Zliss
+
d
*
xe
+
e
*
xze
+
C
+
ε
Table 7.1 provides information on the monthly values of parameter
k
(the speed
at which the effect of distance from the sea decreases) and of other regression
parameters. M refers to the month of the year in which the values were measured.
e
-d/k
ze
-d/k
xe
-d/k
xze
-d/k
M
K
Z
Cte
R
1
2
3
4
5
6
7
8
9
10
11
12
43
47
43
60
144
2959
3337845
44005838
185
33
39
39
-2.1E+01
-6.4E+00
-5.7E+00
2.0E+00
2.1E+01
8.4E+01
2.3E+04
8.4E+05
2.3E+01
-9.2E+00
2.3E+00
-1.9E+01
1.1E-0.1
1.5E-01
1.3E-0.1
6.1E-02
5.9E-03
-4.3E-02
-1.5E+01
-9.6E+02
-2.6E-02
2.9E-02
1.1E-01
1.4E-01
-4.6E-03
-4.0E-03
5.1E-04
1.2E-03
8.5E-03
4.5E-02
1.5E+01
9.6E+02
2.3E-02
8.1E-04
3.2E-03
-4.5E-03
1.5E-01
1.1E-0.1
1.0E-01
6.6E-02
1.7E-02
7.7E-03
1.0E-03
2.5E-03
2.7E-02
9.8E-02
1.1E-01
1.7E-01
-1.8E-05
-9.6E-05
-2.4E-05
-5.8E-06
8.5E-06
3.6E-06
1.8E-06
6.6E-06
1.2E-05
2.8E-05
-9.0E-05
-6.6E-06
16
14
18
10
-5
-82
-23337
-842362
-18
15
12
16
0.89
0.86
0.85
0.84
0.73
0.71
0.64
0.78
0.79
0.88
0.87
0.90
Table 7.1.
Monthly values of k and regression coefficients
From the table it can be seen that the median values for summer rainfall (from
May to September) are not greatly influenced by topography, the multiple
correlation coefficient of R is less than 0.8. For the months of May to August
distance from the sea has a large effect on the median values of precipitation
(k>3,000 km). The median rainfall value for the month of December can be
calculated as follows:
d
d
-
-
Pmed
»
-19.20* e
+0.1361* ze
-0.005* Zliss...
43
43
12
d
d
-
-
...+0.169* xe
43
-0.000007 * xze
43
+15.81
The following equation:
d
d
d
d
-
-
-
-
+ε
Pmed =a*e
+b* ze
+c* Zliss+d * xe
+e * xze
+C
te
k
k
k
k
is an approximate equation due to the existence of the local corrective term
ε
. The
local corrective term
ε
possesses a zero average and the value of this term does not
depend on distance from the sea, altitude, etc. Regarding the intrinsic hypothesis, we
are actually dealing with the same conditions in which the process of kriging would
be used. In order to plot this local corrective term on a map, more research needs to
be carried out on its variogram.
As can be seen in Figure 7.8, variograms tend to be spherical. They are also
associated with what is known as a nugget effect, and tend to be anisotropic in
