Applied geomorphology and arid regions
465
44
46
48
50
-
]
1
1
1
1
I
t
I
9
Sample point
08
_ __ n Capillary fringe boundary
re,o-- 10 metre contour
~
Playa basin
06
0
,
Miles
,
4
()
' kms '
J,
06
~176176
98
96
94
92
I_
52
54
1
I
I
T
3.80
~
7.60
~
111"40
5.20
Electrical
conductivity
in pmhos/cm (x104)
56
58
60
62
64
1
r
[
~
I
"I
!.
r
CONDUCTIVITY
AL MUHARRAO
t
08
06
04
02
AL MAN~,MAH
-
00
-
98
-
96
- 94
AR RIF,g,'_~ i
AL GHARBI
AR' RIF,~
ASH SHARO]SITRAH
92
90
88
44
46
48
50
52
54
56
58
60
62
64
66
- 86
- 84
-~ 82
GRID DATA:- Universal Transverse Mercator. Grid Zone 39. Origin. Long 51~ Lat. Equator. Numbered at 2,000 metre intervals.
Figure 19.4. Aggressive ground conditions in northern Bahrain: the capillary fringe limit, and depth to
groundwater beneath the surface (after Power and Water, Unpub. data; in Cooke et al., 1982).
The outcrops of these evaporites around the world occupy a surface area of 60 million klTl 2
(Ford and Williams, 1989); although karst is found mainly in the northern hemisphere, it
appears in all kinds of climates (Klimchouk et al., 1996).
The high solubility of the gypsum in the Tertiary formations of the Ebro Basin, where
conditions are basically semi-arid, has given rise to extensive karstification and a series of
associated dangers (Guti&rez and Guti&rez, 1998). Dissolution is much more marked
where the gypsum is covered by alluvial deposits (glacis, terraces, infilled valleys).
465
44
46
48
50
-
]
1
1
1
1
I
t
I
9
Sample point
08
_ __ n Capillary fringe boundary
re,o-- 10 metre contour
~
Playa basin
06
0
,
Miles
,
4
()
' kms '
J,
06
~176176
98
96
94
92
I_
52
54
1
I
I
T
3.80
~
7.60
~
111"40
5.20
Electrical
conductivity
in pmhos/cm (x104)
56
58
60
62
64
1
r
[
~
I
"I
!.
r
CONDUCTIVITY
AL MUHARRAO
t
08
06
04
02
AL MAN~,MAH
-
00
-
98
-
96
- 94
AR RIF,g,'_~ i
AL GHARBI
AR' RIF,~
ASH SHARO]SITRAH
92
90
88
44
46
48
50
52
54
56
58
60
62
64
66
- 86
- 84
-~ 82
GRID DATA:- Universal Transverse Mercator. Grid Zone 39. Origin. Long 51~ Lat. Equator. Numbered at 2,000 metre intervals.
Figure 19.4. Aggressive ground conditions in northern Bahrain: the capillary fringe limit, and depth to
groundwater beneath the surface (after Power and Water, Unpub. data; in Cooke et al., 1982).
The outcrops of these evaporites around the world occupy a surface area of 60 million klTl 2
(Ford and Williams, 1989); although karst is found mainly in the northern hemisphere, it
appears in all kinds of climates (Klimchouk et al., 1996).
The high solubility of the gypsum in the Tertiary formations of the Ebro Basin, where
conditions are basically semi-arid, has given rise to extensive karstification and a series of
associated dangers (Guti&rez and Guti&rez, 1998). Dissolution is much more marked
where the gypsum is covered by alluvial deposits (glacis, terraces, infilled valleys).