16
Water In Ecosystems: A Non Renewable Resource
Table I. Approximate quantities of water in the various parts of the hydrological cycle with
replacement periods. (from Young et al. [60]).
Category
Total
%of
%of
Annual
Replacevolume
total
fresh
volume
ment
(km 3 10 3 )
recycled
period
(km 3 )
Oceans
1338000
96.5
505000
2654 Y
Groundwater to 2000m
23400
1.7
16700
1400 y
Predominantly
10530
0.76
30.1
-
-
fresh groundwater
Soil Moisture
16.5
0.001
0.005
16500
1 Y
Glaciers and
24064.1
1.74
68.7
-
-
permanent snow
Antarctica
21600
1.56
61.7
-
-
Greenland
2340
0.17
6.68
2477
9700 y
Arctic Islands
83.5
0.006
0.24
-
-
Other Mountain areas
40.6
0.003
0.12
25
1600 Y
Ground ice (permafrost)
300
0.022
0.86
30
10000 y
Lakes
176.4
0.013
10376
17 Y
Freshwater lakes
91
0.007
0.26
-
-
Salt water lakes
85.4
0.006
-
-
Marshes
11.47
0.0008
0.03
2294
5y
Rivers
2.12
0.0002
0.006
49400
16 d
Biological water
1.12
0.0001
0.003
-
-
Atmospheric water
12.9
0.001
0.04
600000
8d
Total water
1385984.61
loo a
Total freshwater
35029.21
2.53
100 a
a Some duplication in categories and sub-categories.