Case Studies - Coastal Lagoons: Ecosystem Processes and Modeling for Sustainable Use and Development - page 461

point depths, distances of separation points from the coast, and overflow velocities for
the five most important streams entering Koycegiz Lake were calculated each month
for inflow mixing analysis. The calculations for average monthly flows indicated that
the distances of the separation points for the streams have a range of 2-100 m. Another
result obtained from these analyses was that there was no plunge point for five streams
for each month of the year, because the lake water is always denser than the stream
water. Internal wave heights calculation results were 10-46 cm for average winds, but
they may increase to several meters for stronger winds observed in the area. In that case,
strong mixing may occur and destroy the picnocline/halocline in the system. For pre-
liminary studies, the CE-QUAL-W2 model was run for hydrodynamic simulations. The
results obtained from these simulations correlate (depth of hypolimnion, salinities, and
temperature) with field data.
Data analysis and verified flow estimation results indicate that the longitudinal
(x) and vertical (z) changes are important for the Dalyan Channel network, therefore
a two-dimensional (longitudinally and vertically), laterally averaging, hydrodynamic
model (x-z model) such as CE-QUAL-W2 would be an appropriate choice. For the
entire system, however, a three-dimensional, hydrodynamic model coupled with a
water quality model would be appropriate. A parallel study for deciding on such a
modeling system has already been initiated.

9.5.1.2.3 Monitoring

9.5.1.2.3.1 Monitoring System Design
In order to understand the nutrient dynamics in the Dalyan Lagoon subsystem
and to collect data for modeling studies, a monitoring system was designed. The
locations of monitoring stations were determined according to the following
factors. 10

• Stations forming the boundary conditions for the system are to be selected.
• The Dalyan Lagoon system consists of channels and lakes. Monitoring
stations are needed to observe the interaction between channels and lakes.
• Stations representing the lakes are necessary.
• Stations along the channels are needed to detect the spatial variations in
the channel systems.

• Stations near the pollution sources are required.

Taking into account these factors, 16 monitoring stations were selected for the
Dalyan Lagoon system, as shown in Figure 9.5.11. Station 0 and Station 14 represent
the two boundary conditions. Station 3 and Station 4 were at the entrance and inside
of Alagol Lake, respectively. Station 8 and Station 9 were selected as the entrance
stations to Sulungur Lake. Station 10, Station 11, and Station 12 were inside Sulun-
gur Lake. Other stations were the subsequent stations along the lagoon channel
system.
Considering the financial and practical limitations it was decided that seasonal
monitoring for 5 years would produce enough data for modeling and quality assess-
ment objectives.