370
Oto-l m
-1 to-2 m
-2to-3m
-3to-4m
-4to-5m
-5to-6 m
-6 to -7 m
c.
"
:a -7 to -8 m
::r
5"
it
< -8to-9m
" iF
-9to-l0m
-10to-ll m
-11 to-12 m
-12to-13 m
-13 to -14 m
-14to-15m
-15to-16 m
C. Hoselmann . H. Streif
I-%
Fig.7 Summing up of the
10
20
30
40
50
60
70
80
90
100
volumes calculated for the
"" ~ ~
"~ " \
\.
" I, t
\
1-m depth intervals between
o and -16 m NN using the
miner's method for calculating reserves, sheet 2716 (ElsfIeth)
different programs occur only in depth intervals between -10 and -16 m NN.
However, it has to be pointed out that the deposits in this depth interval make up
only 1.94% of the total Holocene volume below NN (Fig. 7) .
With respect to the total volume, the results obtained with different computer programs show no significant discrepancies (Fig. 5). This is remarkable,
because all programs applied use different gridding algorithms. ISM uses a
method called minimum tension gridding (Interactive Surface Modeling User's Guide 1990). The MacGRIDZO gridding algorithm uses the weighted least
squares method (MacGRIDZO User Manual 1994). In this test, Surfer for Windows uses a kriging gridding algorithm (SURFER for Windows User's Guide
1995).
Additional test series were carried out with MacGRIDZO to find out to what
extent certain parameters influence the results of volume calculations. The