Geoscience Reference
In-Depth Information
1920
1930
1940
1950
1960
1970
1980
1990
2000
2010
14
A
Hanford
12
30
10
8
20
6
4
10
2
0
0
B
Yoxall
12
30
10
8
20
6
4
10
2
0
0
C
Willington
12
30
10
8
20
6
4
10
2
0
0
D
Gunthorpe
12
30
10
8
20
6
4
10
2
0
0
1920
1930
1940
1950
1960
1970
1980
1990
2000
2010
Figure 21.3
Minimum dissolved oxygen concentrations (closed symbols) and taxon richness shown as the number of
BMWP-listed macroinvertebrate taxa (N
taxa
- open symbols) at four sites on the River Trent (Figure 21.1). Dotted
horizontal lines show 5 mg L
−
1
dissolved oxygen.
