132
U. Shavit et al.
2.2 Discharge Measurements
Figure 3 shows water-volume and flow-rate data taken at the Naharayim station.
The figure demonstrates the few flood events that took place in 1991-1993. The
insert shows that, apart from flood events, the flow-rate is stable around 1 m 3 s'
400
1.6
1.4
... ~ 1.2 f----6:
a.. - • ....t..
•• ~~~-:r __ .;.
- - E. 1
-
! (UI
~ U.6
' -
£ 04
U.2
0
r-12109198
21/12198
31103199
100
\... • ...J.
,
!.
I.
I
I
I
10/90
1192 1/93 2/94 2/95 2/96 2/97 2/98 2/99
5100
o
Fig. 3. Monthly water volume measured at the Naharayim hydrometric station,
1990-2000. The insert shows flow-rate measurement during winter 199811999
In order to obtain flow-rate data and conduct local mass balance calculations, a
portable acoustic Doppler velocimeter (3D Argonaut-ADV, Sontek), a portable
electromagnetic current meter (Marsh-McBimey 2000 Flo-Mate), and a tilted bar
instrument were used to measure the velocity in cross-sections of the river and its
tributaries. Flow-rate was obtained by integrating the measured velocity across the
river and tributaries.
River velocities were measured using the 3D Argonaut-ADV. Its geometry
defines a measurement volume of 0.25 cc at a fixed distance of 10 em from the
transmitter. Using integrated compass and tilt sensors the velocity vector is given
in earth coordinates. Each sample represents an average of 100 samples (taken at
10Hz), and includes the velocity, the depth of the sampling volume, distance to
boundary, and standard deviations of all parameters. The standard deviation of the
velocity consists real variations and Doppler noise. The noise level of the
instrument affects the velocity by 1 % of the measured value. In general, turbulent
and other variations are larger than the instrument noise. A high concentration of
suspended particulate matter is typical for the Lower Jordan River. As a result, the
signal strength was higher than the noise level by about 35 dB. Due to access
difficulties, we have developed a procedure that allows us to obtain velocity
U. Shavit et al.
2.2 Discharge Measurements
Figure 3 shows water-volume and flow-rate data taken at the Naharayim station.
The figure demonstrates the few flood events that took place in 1991-1993. The
insert shows that, apart from flood events, the flow-rate is stable around 1 m 3 s'
400
1.6
1.4
... ~ 1.2 f----6:
a.. - • ....t..
•• ~~~-:r __ .;.
- - E. 1
-
! (UI
~ U.6
' -
£ 04
U.2
0
r-12109198
21/12198
31103199
100
\... • ...J.
,
!.
I.
I
I
I
10/90
1192 1/93 2/94 2/95 2/96 2/97 2/98 2/99
5100
o
Fig. 3. Monthly water volume measured at the Naharayim hydrometric station,
1990-2000. The insert shows flow-rate measurement during winter 199811999
In order to obtain flow-rate data and conduct local mass balance calculations, a
portable acoustic Doppler velocimeter (3D Argonaut-ADV, Sontek), a portable
electromagnetic current meter (Marsh-McBimey 2000 Flo-Mate), and a tilted bar
instrument were used to measure the velocity in cross-sections of the river and its
tributaries. Flow-rate was obtained by integrating the measured velocity across the
river and tributaries.
River velocities were measured using the 3D Argonaut-ADV. Its geometry
defines a measurement volume of 0.25 cc at a fixed distance of 10 em from the
transmitter. Using integrated compass and tilt sensors the velocity vector is given
in earth coordinates. Each sample represents an average of 100 samples (taken at
10Hz), and includes the velocity, the depth of the sampling volume, distance to
boundary, and standard deviations of all parameters. The standard deviation of the
velocity consists real variations and Doppler noise. The noise level of the
instrument affects the velocity by 1 % of the measured value. In general, turbulent
and other variations are larger than the instrument noise. A high concentration of
suspended particulate matter is typical for the Lower Jordan River. As a result, the
signal strength was higher than the noise level by about 35 dB. Due to access
difficulties, we have developed a procedure that allows us to obtain velocity