Water Sources and Quality Along the Lower Jordan River
129
(Starinsky 1974). These include seawater evaporation and salt crystallization (e.g.,
low NalCI and high Br/Cl ratios), gypsum precipitation and sulfate reduction (low
sulfate), and extensive water-rock interactions such as dolomitization (Ca
enrichment and low 87Sr/86Sr ratios) and clay adsorption (low BlLi and high «sllB
values) (Starinsky 1974). The last phase of the fluviatile episode, 100 to 20 Ma
B.P., was the formation of the long and narrow Lake Lisan. Lake Lisan was a
hypersaline waterbody with a sharp density stratification of freshwater overlying
hypersaline brines. Since then, great variations have occurred, including extensive
evaporation, level fluctuations (500 - 180 below sea level), and salinity changes
(Yechieli et al. 1993). The present Jordan River flows through the Lisan
Formation, that is composed of marls and gypsum sediments.
Figure 1 shows the Lower Jordan River region. It also shows the Yarmouk
River which marks the border between Israel, Jordan, and Syria. At present, the
outlet of Lake Tiberias and the outlet of Yarmouk River are blocked by dams.
Water from saline springs at the shore of Lake Tiberias is carried by the saline
carrier to Alumot, the starting point of the Lower Jordan River. A total of20 mcm
yea{1 of saline water and about 7 mcm yea{1 of sewage is the initial discharge of
the river.
The total agricultural irrigated area that drains back to the river was estimated
as 440 km 2 ; 170 km 2 on the west side (Tahal 2000) and 270 km 2 on the east
(Salameh 1996). The total water consumption for irrigation was estimated as 400
mcm year-I in the east side (Salameh 1996) and about 150 mcm year-I in the west
side (Tahal 2000). An analysis of the agricultural influence on the river mass
balance is a major challenge of the current study. The above publications have
suggested using a general estimate, suggesting that about 15% flows back to the
river. This estimate will be tested against our results.
The monitoring system of the Lower Jordan River is inadequate. Water level
and discharge are measured currently at only one hydrometric station near
Naharyim. Partial and insufficient water sampling and chemical analysis are
obtained twice a year by the Israeli National Reserve Authority (INRA). Sporadic
discharge measurements and water samples were taken in the past; however, old
discharge data of the river and its inputs are often conflicting and inconsistent.
General estimates were published in the past (Salameh 1996; Tahal 2000) and can
be currently obtained (see http://systemforschung.arcs.ac.atljowapubl and
http://www.gtz.de). There is a clear need for a better-organized and rigorous
monitoring system of the river and its inputs and outputs.
The objective of the study is to evaluate the different components that presently
control the quality of water in the river. In particular, the study is looking for ways
to assess the role played by the subsurface contributions. The research program
includes water sampling for chemical and isotope analysis and flow-rate
measurements using a mobile acoustic Doppler system. The study results will be
used to develop a conceptual model by which both flow-rate and chemical
composition of the subsurface input will be quantified.
129
(Starinsky 1974). These include seawater evaporation and salt crystallization (e.g.,
low NalCI and high Br/Cl ratios), gypsum precipitation and sulfate reduction (low
sulfate), and extensive water-rock interactions such as dolomitization (Ca
enrichment and low 87Sr/86Sr ratios) and clay adsorption (low BlLi and high «sllB
values) (Starinsky 1974). The last phase of the fluviatile episode, 100 to 20 Ma
B.P., was the formation of the long and narrow Lake Lisan. Lake Lisan was a
hypersaline waterbody with a sharp density stratification of freshwater overlying
hypersaline brines. Since then, great variations have occurred, including extensive
evaporation, level fluctuations (500 - 180 below sea level), and salinity changes
(Yechieli et al. 1993). The present Jordan River flows through the Lisan
Formation, that is composed of marls and gypsum sediments.
Figure 1 shows the Lower Jordan River region. It also shows the Yarmouk
River which marks the border between Israel, Jordan, and Syria. At present, the
outlet of Lake Tiberias and the outlet of Yarmouk River are blocked by dams.
Water from saline springs at the shore of Lake Tiberias is carried by the saline
carrier to Alumot, the starting point of the Lower Jordan River. A total of20 mcm
yea{1 of saline water and about 7 mcm yea{1 of sewage is the initial discharge of
the river.
The total agricultural irrigated area that drains back to the river was estimated
as 440 km 2 ; 170 km 2 on the west side (Tahal 2000) and 270 km 2 on the east
(Salameh 1996). The total water consumption for irrigation was estimated as 400
mcm year-I in the east side (Salameh 1996) and about 150 mcm year-I in the west
side (Tahal 2000). An analysis of the agricultural influence on the river mass
balance is a major challenge of the current study. The above publications have
suggested using a general estimate, suggesting that about 15% flows back to the
river. This estimate will be tested against our results.
The monitoring system of the Lower Jordan River is inadequate. Water level
and discharge are measured currently at only one hydrometric station near
Naharyim. Partial and insufficient water sampling and chemical analysis are
obtained twice a year by the Israeli National Reserve Authority (INRA). Sporadic
discharge measurements and water samples were taken in the past; however, old
discharge data of the river and its inputs are often conflicting and inconsistent.
General estimates were published in the past (Salameh 1996; Tahal 2000) and can
be currently obtained (see http://systemforschung.arcs.ac.atljowapubl and
http://www.gtz.de). There is a clear need for a better-organized and rigorous
monitoring system of the river and its inputs and outputs.
The objective of the study is to evaluate the different components that presently
control the quality of water in the river. In particular, the study is looking for ways
to assess the role played by the subsurface contributions. The research program
includes water sampling for chemical and isotope analysis and flow-rate
measurements using a mobile acoustic Doppler system. The study results will be
used to develop a conceptual model by which both flow-rate and chemical
composition of the subsurface input will be quantified.