Water Sources and Quality Along the Lower Jordan River
139
3000
River water
2500
"""'
2000
•
~
S 1500
'-'
0
• •
1000
• Yarmouk water
500
0
0
200
400
600
800
1000
S04 (mg/L)
Fig. 12. Cl versus S04 of river samples between Alumot and Shifaa representing all the
sampling trips. The linear curve represents theoretical mixing between Alumot waters and
Yarmouk waters
The 87Sr/86Sr ratio (Fig. 13) decreases from 0.70775 to 0.70763 from 0 to 20
km downstream. The groundwater and western surface inflows along the upper 20
km have significantly higher 87Sr/86Sr ratios (0.7078 to 0.7091), which cannot
account for the isotopic shift. In contrast, the Yarmouk River (0.70716) and
shallow groundwater below a fishpond (0.70741) have isotopic ratios that are
consistent with the isotopic modification of the river. It seems that the
anthropogenic groundwater component has a low 87Sr/86Sr signature that is
different from that oflocal western saline springs with higher 87Sr/86Sr ratios.
In the upper zone the gradual decrease in salinity is associated with a general
(although with large fluctuations) increase in 0 18 0 values. In contrast, the 0 18 0
values of springs and observed runoff are low (-4%0). Hence, the oxygen isotopic
modification is also inconsistent with western inflows. We observed very high
0 18 0 values in fishponds and in shallow groundwater below the fishpond. The
large fluctuations of the 0 18 0 values probably reflect both inflows of 0 18 0_
enriched groundwater superimposed with surface evaporation.
Assuming that the chemical compositions of conservative elements reflect a
mixing of the upstream water (Alumot Dam) and the water found in the Yarmouk,
we calculate the flow-rate ratio, f, of the upstream initial discharge at Alumot
divided by the mixed total flow-rate along the Jordan River,
f = C mu - CYarmouk ,
Cinitial - CYarmouk
(1)
139
3000
River water
2500
"""'
2000
•
~
S 1500
'-'
0
• •
1000
• Yarmouk water
500
0
0
200
400
600
800
1000
S04 (mg/L)
Fig. 12. Cl versus S04 of river samples between Alumot and Shifaa representing all the
sampling trips. The linear curve represents theoretical mixing between Alumot waters and
Yarmouk waters
The 87Sr/86Sr ratio (Fig. 13) decreases from 0.70775 to 0.70763 from 0 to 20
km downstream. The groundwater and western surface inflows along the upper 20
km have significantly higher 87Sr/86Sr ratios (0.7078 to 0.7091), which cannot
account for the isotopic shift. In contrast, the Yarmouk River (0.70716) and
shallow groundwater below a fishpond (0.70741) have isotopic ratios that are
consistent with the isotopic modification of the river. It seems that the
anthropogenic groundwater component has a low 87Sr/86Sr signature that is
different from that oflocal western saline springs with higher 87Sr/86Sr ratios.
In the upper zone the gradual decrease in salinity is associated with a general
(although with large fluctuations) increase in 0 18 0 values. In contrast, the 0 18 0
values of springs and observed runoff are low (-4%0). Hence, the oxygen isotopic
modification is also inconsistent with western inflows. We observed very high
0 18 0 values in fishponds and in shallow groundwater below the fishpond. The
large fluctuations of the 0 18 0 values probably reflect both inflows of 0 18 0_
enriched groundwater superimposed with surface evaporation.
Assuming that the chemical compositions of conservative elements reflect a
mixing of the upstream water (Alumot Dam) and the water found in the Yarmouk,
we calculate the flow-rate ratio, f, of the upstream initial discharge at Alumot
divided by the mixed total flow-rate along the Jordan River,
f = C mu - CYarmouk ,
Cinitial - CYarmouk
(1)