Chapter 6 . Stream Assessment
101
1 ()() /.
90
i
80
!E;j?
70
t:!_
60
!!l.,
~~
50
ti i!
40
~.=
30
0
20
u
10
0
~ ~ ~
:::. e
~ i
~
Cl
'"
1
~
Macroinvertebrate Frequency of Occurence
Fig. 6.6. Prediction of macroinvertebrate taxa in the Zwalm river basin based on
ANNs compared to simple probabilistic guesses.
~
1
c: 0.9
~ 0.8
~ 0.7
~ 0.6
o 0.5
~ 0.4
~ 0.3
2 0.2
e 0.1
a.. 0
o
Hydrophilidae
---.............
~
"' "
"" "' " ,
'" -........
--0.2 0.4 0.6 0.8
1.2 1 .4 1.6 1 .8
Flow velocity (m/s)
Fig. 6.7. Probability of presence predicted by the ANN for
Hydrophilidae in relation to flow velocity.
2